[JHill]

Installed a SB con ofe clutch ,about 1k miles on it now .
you guys that thave swaped from stock to SB did you notice any more noise (rollover) in nuetral ? mine is terrible, had zero noise with the stocker. is there a heavyer fluid thats safe to run in a ZF? any help much appreciated

 

[gregrob]

My buddy switched to 50wt gear oil in his ZF5.

Gear oil is thinner for the same viscosity than motor oil, so it's not as thick as you would think.

It is holding up way better than ATF or Synth motor oil, that stuff would be cooked in 5000 miles. It stopped a hard shift from 1-2 though, used to be notchy and grind sometimes, now it goes in smooth.

May give that a shot.

He used synthetic 50wt gear oil.

 

[Calico5]

Mine rattles quite a bit more now in neutral (with the DD) than it did stock. I've tried a couple of different kinds of lube in it, but it still makes noise (haven't tried and gear lube though).

Also, it used to "growl" on take-off in 1st or 2nd gear, from right below idle to about 800 rpm. Now it's gone in 1st & 2nd, but it's got the growl in other gears, 3rd & 4th...and at a higher engine/road speeds(12-1500 rpm).

Other than that, it's working great! At least it isn't slipping with a load on it!

 

[JHill]

i would have expected the DD to make noise in N after talking to Peter @SB.
not un-happy at all with the performance so far.
just didnt expect more noise in the a.m. than the motor makes

 

[69W900A]

Gear oil is not thinner than engine oil for a given viscosity.

Gear oil is thinner than engine oil in SAE weight labels since they use different tables for gear and engine oils.

An SAE 85w90 gear oil is very similar in viscosity to an SAE 10w40 engine oil.

 

[Deerezilla]

My buddy switched to 50wt gear oil in his ZF5.

Gear oil is thinner for the same viscosity than motor oil, so it's not as thick as you would think.

It is holding up way better than ATF or Synth motor oil, that stuff would be cooked in 5000 miles. It stopped a hard shift from 1-2 though, used to be notchy and grind sometimes, now it goes in smooth.

May give that a shot.

He used synthetic 50wt gear oil.

where did you find 50w gear oil?

 

[jopes]

My buddy switched to 50wt gear oil in his ZF5.

Gear oil is thinner for the same viscosity than motor oil, so it's not as thick as you would think.

It is holding up way better than ATF or Synth motor oil, that stuff would be cooked in 5000 miles. It stopped a hard shift from 1-2 though, used to be notchy and grind sometimes, now it goes in smooth.

May give that a shot.

He used synthetic 50wt gear oil.

your syncros are probably getting worn out, hence the thicker oil took up that little clearance.

ZF's are made from the factory to run on ATF and running somehting thicker will definatly lead to a premature failure at some point.

 

[gregrob]

your syncros are probably getting worn out, hence the thicker oil took up that little clearance.

ZF's are made from the factory to run on ATF and running somehting thicker will definatly lead to a premature failure at some point.

What makes you think 50 wt gear is thicker than ATF? The relative viscosities are close to the same at the normal temp range for a transmission. See the chart in the fluids section.

 

[gregrob]

where did you find 50w gear oil?

He works in a truck shop and that's what they fill the gearboxes in the road tractors with. I'll have to ask him where they source it.

 

[gregrob]

Here is said chart:

 

[Aljay]

The 50w he is talking about is a synthetic. I know because that is what my eaten fuller specs to use.

 

[69W900A]

It's not really "synthetic" as in most cases the Eaton LL trans and diff oil is gpIII baseoil, still very good stuff though.

Most typical ATF's have a [email protected]*C of about 7.5cST. Exceptions are the modern lightweight ATF's like Mercon SP and the latest Dextron Spec.

Any truck shop will have 50wt trans oil. A lot of truck stops will carry it as well.