Shift Linkage Adjustment or clutch drag?

Did you source the McLeod from Dennis?

I would call him and get his thoughts in any case.

Larry

quote:

Originally posted by LF - TP 2511:
Did you source the McLeod from Dennis?

Yes. It was the second one he had sold at the time.

quote:

I would call him and get his thoughts in any case.

Did that way back when. He was scratching his head. After all the obvious stuff with linkage and clutch bleeding, checking initial throw, etc, he suggested I try shimming to higher intial clearance on the clutch. Big job. Figured I do it when I yanked the engine but try all else until then. It's a july and August problem.

Kelly

I have a friend with the same setup from Dennis and it works great. He is using a standard slave though.

If I had that problem, I would figure out how to reliably measure the total movement of the clutch shaft arm (the one that the slave connects to) and then measure it cold and hot. The movement should be the same cold or hot. If it is not, something is messing up on the hydraulic side of the system. If it is the same, then something is going on with the clutch system or the ZF main shaft.

On a problem like you are having, it will help immensely if you can separate parts of the system and then focus in on the root cause. If the hydraulic clutch part is working correctly, you can focus on the clutch release movement hot and cold, etc.

Mike

Kelly,

Has this clutch been working correctly for a while, and then the problem just started? If so, perhaps the master cyl is by-passing. Try pumping the clutch pedal to see if that helps.

There may be too much marcel in the disc(s). This would effectively make the clutch disc thicker (than normal) when it (the clutch) is disengaged.

The shift linkage isn't the problem.

John

Is the clutch arm (where the slave pushrod connects) close to vertical or leaning slightly forward? If it is leaning aft of vertical, you may be able to rotate it one spline forward.

John

I have the same clutch /flywheel in my GT40 and it works great hot or cold.
Have you given any thought to the pilot bearing hanging up on the input shaft when it gets hot?
I can't seea linkage adjustment problem only manifesting itself when hot.

Ron

quote:

Has this clutch been working correctly for a while, and then the problem just started?

The problem has been there for several seasons albiet less severe when I originally got the car back from Dennis. It was early fall and I really didn't see much of it until the next season. Yesterday was 93F and I drove for about an hour. Typical summer day. Symptoms were the worst ever. The guy that originally delivered the car was a hammer handed dude and had knocked the linkage out (it may not have been tight?) upon delivery. So adusting the linkage was my first job after I limped home in third on it's maiden drive. That was three years ago. Obviously, I need to address it. Just haven't had a helper when the problem has occured to repeat some of the things I have previously checked on travel hot and cold.

quote:

If so, perhaps the master cyl is by-passing. Try pumping the clutch pedal to see if that helps.

Yup, all good thoughts John. Several seasons ago, Quella thought it might have been a bad master and sent me a one that I swapped in and thoroughly bleed the system at that time (and every season). It had no affect on the issue.

quote:

There may be too much marcel in the disc(s). This would effectively make the clutch disc thicker (than normal) when it (the clutch) is disengaged.

I said too little marcel, but you are correct John, too much would create the same problem and it would be double the issue on a dual disc stack.

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The shift linkage isn't the problem.

Agreed with the caveat that there isn't movement in the engine mounts that's interfering with the shift linkage travel. Sort of a long shot but I need to check it. I noticed the shift rod is pretty close to my 10 qt pan.

quote:

On a problem like you are having it will help immensely if you can separate parts of the system and then focus in on the root cause. If the hydraulic clutch part is working correctly you can focus on the clutch release movement hot and cold, etc.

Agreed Mike. Easier said than done on an intermitten problem. I'll systematically get there.

Won't be able to get to it for a week or so. Thanks for the feedback so far. Open to all other thoughts and input until then.

Best,
K

quote:

I would figure out how to reliably measure the total movement of the clutch shaft arm (the one that the slave connects to) and then measure it cold and hot. The movement should be the same cold or hot. If it is not, something is messing up on the hydraulic side of the system. If it is the same, then something is going on with the clutch system or the ZF main shaft.

Mike

I like Pantera 1887 suggestion whether it pertains to your issue or not, that is a good idea. I had issues with my new Slave after driving, and I found several issues causing it. Does the clutch peddal feel the same all the time, whether hot or cold? I would measure the travel distance of that puppy like 1887 suggests, hot and cold. Maybe also try how it performs when just letting it warm up in the driveway without driving, not sure what that may prove, but what the hey. Without pumping the pedal, press the pedal measure once at cold, then let it warm up real good sitting there, press the pedal once and measure again. Use the wife if needed...mine is used to it.

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Originally posted by MARLIN JACK:
...Read this very carefully! I had the same problem with a Second Pantera I sold a few years back! I was always 'Fighting' to get it into Reverse and First. It was a simple problem that the 'Back-Up Indicater Light', SWITCH was screwed ALL THE WAY IN; preventing the 'Cross-Shaft', with-in the 'Small Shifter Box'(the one Mounted on the Left Rear of the ZF) From Sliding TO THE LEFT.

Before You pull everything apart to check the clutch, First, BACK/UNSCREW the Switch OUT and give the Shifter One more try! You Might Be Lucky There!

Unless I’m misreading his original post, it goes fully into gear fine with the engine not running.

Mike

Kelly,

Have you run this by Red Roberts at McLeod (714-630-3668 Tech Dept)?

John

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Originally posted by r mccall: Have you given any thought to the pilot bearing hanging up on the input shaft when it gets hot?
Ron

hadn't considered that but would fits the symptoms. Sort of odd since I can shift into other gears though second can take an unusual amount of force, but no grind while at the same time 1st and reverse are NFW. This was a new Dart block and I didn't build it. Since it's a street car I presume it was just an ordinary bronze pilot bearing. Thanks for that Ron. Another one to check. Kelly

Seems like a perennial occurrence; weather warms up into the 90s and the shifting starts acting up when the ZF gets good and hot. It was the norm that cold, and/or, not running, any gear can usually be had very smoothly. Hot, it starts getting a little heavy getting in and out of gear like it’s hanging up a bit. Hot means 90F ambient temperature and I’ve been beating it around pretty good or even just prolonged highway speed. Although it’s possible that it is the clutch discs hanging a bit, or maybe even the pilot bearing as Ron suggested, I’m thinking not. This year was a little different.

This year, after early season driving without issue, last night I go out for the evening and after I walk out to my car after it has been sitting and I literally could not get reverse or first, period. Not with or without the engine running. I remove the gate and problem solved so I figure something came loose or shifted in the linkage. It definitely did not. I’ve been doinking around with this for quite a while so I have marked the positions of every u-joint and spline in the shift linkage. All were tight. No movement. Hmmmm? So I’m thinking the engine isolators must have relaxed a bit, enough such that it changed the initial setting of the linkage. At first I was skeptical this could produce enough movement to do this but after trying to have my wife hold the shifter while I repositioned and tightened the linkage, I was surprised by just how small of differences in the initial linkage position significantly affected shifting performance. I actually found I even needed to hold the u-joint downstream of the where I was tightening the turnbuckle else the loose end of the linkage would turn while I was tightening it, and even this was enough to affect the initial setting and shifting behavior.



I remembered Ron McCall posting that he had made a couple of wooden blocks to hold the shifter in the gate so I figured I’d give that a try. Tap them in place with a plastic mallet and it works very well. Standard tool in my kit now and I’d recommend it to everyone. But I had another surprise. The position of the linkage that makes every gear engage silky smooth even while running hot makes it impossible to get reverse in any condition; hot, cold, engine running or not! ??? So I removed the gate and no problem. Hot shifting, cold shift, engine off, all seems great. This is starting to annoy me, so I put the gate back on and just started experimenting a little by biasing the shifter with the blocks. The shift lever biased to the right as shown allows access to all gears and is functional but has the “sticky” feeling after hard running and requires a fair bit of pressure to get second and third while hot, and also produces some bad engagement of first and reverse.



So to recap, the position that allows optimum feel and performance shifting 1-5 even while hot completely denies reverse with the gate on. Remove the gate and no problem. The position that allows all gears and reverse performs somewhat poorly hot but seems fine cold. This winter there will be an engine and ZF swap, otherwise I’d put more effort into this and might even be tempted to make a new gate to accommodate the optimum linkage position. In the mean time, I think I’ll just run without a gate and enjoy. I just don’t want to transfer the problem post engine/ZF swap.

1. I’ve checked clutch travel hot and cold; though I’ve suspected it for a while, there just doesn’t seem to be an issue here based upon how it feels and there’s not even a hint of the car wanting to travel on flat ground with clutch engaged in any gear.
2. As Marlin had suggested I did check whether the reverse switch was causing some interference with reverse in the best 1-5 position but this made no difference.
3. I also checked to make sure the trunion support was still tied down tight and it was. Not sure I mentioned it but I do have the Pantera Performance conversion to a close fitting rod through a rod end instead of the rubber isolated trunion.
4. The motor mounts are not urethane. They are OEM style rubber and do not appear to have relaxed or deformed discernibly. I’m thinking maybe I need to pull the mounting screws down and compress the isolators a bit and see if that stabilizes things.

I’m still feeling a bit surprised by how precisely the linkage needs to be set. Anyone else had similar issues? It’s got me scratching my head a bit.

Best,
Kelly

It sounds as if you have slop in the shifter shaft along the way; so, all your side to side movement is not being transmitted to the ZF. The likely culprit, if your u-joints are sound and your connections are tight, is in the mounting of your gearshift lever to the shifter shaft. The bushings may be worn and your motion not fully translated. The whole unit is easily removed from the car. It probably wouldn't hurt anyway as a lot of crap collects down there over time. I don't remember the mechanism exactly; however, it seems to me we remedied similar worn parts with a larger pin from Ace hardware and shims in the past.

I think you are fighting slightly worn components in all points of movement in the ZF and linkage.

I have milled out the fingers in my gate, except reverse, and have no problems finding a gear in any situation. You might want to consider that modification.

quote:

Originally posted by JTpantera: It sounds as if you have slop in the shifter shaft along the way;

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Originally posted by Dave2811: I think you are fighting slightly worn components in all points of movement in the ZF and linkage.

Well, I’m open to any and all suggestions thus my post and that's certainly a sensible premise. It's a pretty low mile car (22kmile now). I can say this, the u-joints in the linkage appear very sound. The ones at the rear are of course easy to verify and at least to the extent the translation of the shifter linkage to the u-joint visible when you remove the ashtray goes, that also appears sound and the most minute shifter movement is visible. Also, when I grab the u-joint under the ashtray and move the shifter, it sure feels true and free of slop. Not opposed to pulling shifter bucket though as it is relatively low time investment. After all these years though, I cant say the gate adds much value. If I don’t know where 1-5 are at by now I should hang it up.

K

Some of the aftermarket shift gates have the reverse slot further to the left than the OEM gate. There's one on eBay right now (item # 251082471906) but I believe Precision Pro-formance sells the same one. They have them in polished aluminum too, for more of an OEM look.

...I have gone over All of the Previous Posts!
Here's what I come Up with!
1. The 'Rod End' Trunnion Bearing! Should be Adjusted to the 'Maximum Height', And Allow the Shifter Rod to CLEAR the Halfshaft U-Joint, by Only 5/8"-3/4"! Has The ROD and Trunnion Ever Been Greased(NOT Oil!)?? It Must have Lubrication! The 'Rod' gets Hot, Expands MORE than the Bearing; and Binds in the Rod End! Here is where You get the 'Sticky' from! Remember, the Rod runs right under the Header!
2. Your Shifting Problem started when You Installed the 'Twin Disks'? Two disks, Obviously, are Thicker than a Single Disc...On the 'Slave' Cylinder there is an Threaded 'Adjustment' at the Small Linkage that connects the Slave to the Lever, I would Adjust that OUT More to 'Tighten' Up the 'Disengagement' of the Clutch...Right Up 'Near' the Point where 'ENgagement' Occurs!
The Disks Heat-Up, Gain in Thickness, and Drag Power to the Trans as Your Trying to Engage Gears!
3. GET RID OF THE GATES!!!! ALL of the Gates! Stop Playing with the Shifter Rod!!...If that were the Problem! The Problem would be there, when Cold!! You have it Near Centered! That's All You Can Do! This Machinist is telling You! By Their Design, the 'Gates' Will NEVER Match-Up to the Requirements of the Gearbox!! Even though, Some think they Do, They are Off as MisMatched! To Make It Simple! You Are Fighting In the Middle of a 'War' Between the Slots on a Plate and the Position the Transaxle 'Selectors' NEED to be In; to Achieve a Smooth, 'Completed' Mesh of Syncros To Gears! The Plate Hinders Full Movement of the Shift Lever, Not Completing Full Shifts.
4. Are You using 80W-90 Gear-Lube in the Gearbox?
5. Have You Confirmed..there IS Grease in the 'Shifter Box'? The little Box on the Side of the Transaxle, that the Shifter Rod Connects To.
Now...Are You aware of what the 2 little Rubber Plugs are Hiding, underneath that Same little Box? You need to get under the Transaxle to see them! They Hide 2 Set-Screws! These set screws Loosen-Up, All the Time!! They keep the 'Internal' Crank Lever; Tight on the 'Crosshaft'! Ofcorse, as stated earlier, If that were the Problem...It would Happen when Cold! Unless 'IT' Only Loosens-Up after it gets Hot!
One More thing about those 2 Setscrews; The Only way to check them is to pull the 4 Bolts on the Cover and LOOK in there while moving the Shift Rod, and See if the...It's a Lever/Crank Mounted on a Cross-Shaft, With a 'Ball and Socket' Joint on the End of the Lever!(and THAT had Better Be Well Greased!!) It gets NO Oil from the Main Box! You must Visually Verify IT Does Not Slip on the Shaft!
Now get this...You can Get to the Set Screws with a 'T' handle 'Allen' Wrench; Just by pulling those Plugs out! That's Why They're-There!! I'am NOT betting 'This' is the Problem! But it Can be a Hidden and UNdetectable 'Lose of Motion'! I recommend they be checked Often and when any Shifting Problems Arise.

Take My Advice for what it's worth! I've Driven My Pantera for 11 Years...Never had a Shifting Problem! I DO Run the Oilite Bronze Pilot Bearing! I threw the Original Gated Plate in the Trash, the Day I Purchased the Pantera, I Machined My Own 'Fingerless' Plate!!

If I come up with more thoughts, I'll get back to You!...

Kelly,

If you wanted to keep the stock look of the shifter plate, you could mill the left side of the reverse slot.

John

2
This Plate Shows the Minimum Clearence Required for NoN-Binding Shifts!! Just Milling Off the Fingers, Does Not provide enough Clearence on Width and Length!
Don't Believe Me? I'am Not The One 'Grinding Gears'! I didn't 'Scratch My Head'; I Studied and then Solved; the Problem!!...

with a not too worn and properly adjusted linkage, shifter gate is not a problem.

Just my $0.02

I am running the fingers and my car shifts perfectly both hot and cold.

Marlin I appreciate your suggestions and there are several I will run down.

There didn’t used to be a problem and now there is. It's not like I haven't been able to adjust it to a functional level, it's more a matter of tune and understanding the reason for the linkage coming out of tune. Something has changed or maybe it is just wear. I don’t think it’s an issue internal to the ZF because it works very smoothly and precisely when properly adjusted without the gate hot or cold; like it used to work with the gate. This would still seem to suggest linkage to me. Wear or slop does not appear to be the issue but I will check the guide bearing as suggested just to be sure. I’ll eventually find the culprit. I think I’ll put it up on the lift when it is acting up and observe the linkage motion. In the mean time, though internet troubleshooting can be nebulous, I appreciate everyone’s thoughts on the matter.

Best,
K

Heavy handed editing provided by your administrator.

Don't take my actions the wrong way, I appreciate the way you guys handled yourselves, you have my heartfelt thanks.

I won't lock the thread unless the problem persists.

I had to do this in a hurry, I have a day job afterall ... at least for a few more months.

One suggestion where we can improve, always address your replies to the original poster, the person who started the thread. Keep on topic. Never critique the replies of another member. State your opinion without invalidating the opinion of others. Those are the terms of service, and they work pretty good.
_____________________________

Getting back on topic, my Pant shifted OK, but the shift lever really dragged in the gate, and no amount of adjustment could eliminate the drag in every slot, so I took my die grinder and ground the slots everywhere the lever was dragging, until the lever no longer rubbed the gate anywhere. One of the gate fingers ended being paper thin! But man what a difference! The amount of effort needed to shift was dramatically reduced.

FWIW Gary Hall was also opposed to the gated shifter.

Kelly, the way you described the problem being heat dependent, the first thing that came to my mind was when's the last time you changed the transaxle fluid, and what type of fluid did you put in it? I'm just throwing that out there for what its worth.

-G

Kelly I will add this by comparison ... I have the same exact issue ..car shifts fine and when it heats up shifts very hard ...cant down shift and have to press it into gears ... the difference is mine is single disc, and I replaced the master and slave ... the problem always seems to come back ... i think George might be on to something with the gear lube ...because I did change it because and the problem subsides for a short period of time then returns.

Ron

quote:

Originally posted by accobra:
.. ... i think George might be on to something with the gear lube ...because I did change it because and the problem subsides for a short period of time then returns.
Ron

I can confirm that the wrong gear lube can make shifting difficult when hot. I had a high tech, heat activated industrial gear lube that when hot, got slippery and the synchros refused to bite. Shifting was almost impossible.

Changed to bottom shelf API GL4, 80W-90 and all is well.

Lube gets changed at the beginning of every season. I've been working and traveling a lot so probably only log 3k miles per year or so; sad but so. Ya-know, regarding the lube, this does seem to coincide with my use of Valvoline Durablend, or at least the aggravation of the condition. It's 80W/90 but is a synthetic blend. Maybe I'll go back to good old dino lube and see if it behavior improves. The RBT-2ZF in my GT40 sure seems to like it and I beat the piss out of it.

I'll probably remove the gate too. I figure if the shifting engagement feels good, it probably is much easier on the syncros and something that easily engages lessens the likelihood of missing a gear. I use 1-5 much more often than reverse. Can't say I really care if the gate is there. Just a bit bemused about the change. Thanks for your replies and I'll keep you all posted.

Best,
K

One more area that sometimes affects shifting, and has nothing to do with the ZF. If the motormount rubbers are deteriorated, the engine can shift around relative to the shift-shaft support under the left header. This area NEVER gets lubed and can bind up when the powertrain moves.
Conversely, I've found Panteras in which the shift shaft support nut loosened up, causing the exact same problem as the support moved. Only takes a minute to check...

quote:

Originally posted by Bosswrench: One more area that sometimes affects shifting, and has nothing to do with the ZF. If the motormount rubbers are deteriorated, the engine can shift around relative to the shift-shaft support under the left header.

Thanks Jack. It’s getting to be a long thread but I have inspected the isolators. They are rubber not urethane and look great at least as far as visual inspection. They were replaced with new 7k miles ago. I need to put a wrench on the bolts and see if they are pulled up where they should be. I’ll probably measure their compressed height and see if they are moving around. In addition to a list of other things, I’m going to get it on the lift and observe the linkage motion and also take some reference measurements to the frame and see if I can detect movement. Going to try to do one thing at a time to isolate issue.

quote:

This area NEVER gets lubed and can bind up when the powertrain moves……..Conversely, I've found Panteras in which the shift shaft support nut loosened up, causing the exact same problem as the support moved. Only takes a minute to check...

As mentioned earlier, I have checked the trunion support and it is secure. I also have the PPC spherical rod end conversion that has the shifter rod replaced by a close tolerance stainless rod (splines welded back onto ends) that then slides in a thin oilite bronze bushing pressed into the spherical rod end that replaces the standard trunion. It doesn’t require lube and I don’t lube it because that would cause fouling by collecting dust and debri. It slides freely and maintains very precise geometry.

Best,
K

quote:

I....have the PPC spherical rod end conversion that has the shifter rod replaced by a close tolerance stainless rod (splines welded back onto ends) that then slides in a thin oilite bronze bushing pressed into the spherical rod end.....

OK- didn't know which you had. Some conversions use a teflon bushing. Teflon is heat sensitive and I've seen a couple where the bushing (it has a flange on one end, with a setscrew to retain it) has migrated past the setscrew and out of the aluminum holder, making things worse than before.