Transzxle lube

welcome to PI.

from by rememberance of others discussing, a few of the early models had the top fill. BUT the greater majority did not. thus the level check plug (116) IS the fill location

What is the (116) after plug? Do you use EP 90 for limited slip gear lube?

Thanks
Norm

The figure didn't come up when I first looked at the reply. Now I see the 116.

Thanks
Norm

Norm, you'll find many, many threads on ZF lube in the forums. RBT (the manufacturer) recommends regular 80W-90 GL4 gear oil. You can try a synthetic, such as Redline MT90, but you might find it leaks a bit around the gaskets and/or seals.

It's very important to change your gear oil once per year, regardless of mileage, as condensation tends to form inside the case.

Has anyone here replaced the Plug with a Sight Glass?

A sight glass wouldn't be of much use because the oil shouldn't be any higher than the bottom of the hole.

You need a funnel like this and then fill it via the side hole on left hand side until it pours back out from the same hole. It is usually messy. It should take slightly more than 3 liters if properly drained which gives you and idea when to slow down filling.

I (and others) successfuly uses Red Line shockproff lightweight oil which is suited for transaxles and tends to make the syncros Work really well. Concerning synthetic vs mineral and oil spill from seals I have no leaks using the Red Line synthetic.

quote:

Originally posted by Hemihunter:
Has anyone here replaced the Plug with a Sight Glass?

I would like a low profile "L port" valve.

quote:

Originally posted by RRS1:
A sight glass wouldn't be of much use because the oil shouldn't be any higher than the bottom of the hole.

Just drive the right tires over two 2X4's and the level should rise to the center glass

Hemihunter, I don't like making a mess when adding lube to the ZF. So I swapped the fill/check plug for a right-angle fitting, and added a short length of translucent Tygon high- temp hose & worm clamps leading up to an AN fitting & cap on top near the ZF shift box. The cap has a dipstick built-in and I can add lube thru the top of the rig with a funnel. Be careful what sight-glass material you use- we know that the lube can get to 250F under high rpm high-load conditions and not all transparent hose will take that temp without softening or melting, and slipping off the fittings.

Guys I dont want to be sentimental, but the design with the fill hole serving also as an overflow has been working sinse the stoneage. It is common on almost any manual transmission and on final/rear drives as well.

There is really no reason to alter that design in my humble opinion.