Any thoughts on changing the gear oil in the rear end? Does anyone change it after each track event? Before? I've heard a lot about friction modifiers...uh, huh? 
Rear gear lube
- Thread starter Tim M
- Start date
TOM KEISER
Member # 012
I changed mine to Castrol Syntech (synthetic) last year while I was swapping in the new disc brakes, friction modifier is required, about 4 oz. as I recall. You'll find the modifier on the shelf next to the lube at the parts store. Don't bother looking for a cover plate gasket, nobody makes one any more and RTV seals it just fine. You'll need a funnel with a tube on the end to fill it back up.
- Thread starter
- #3
What does friction modifier do that the lube can't do by itself?
Kerry & Kathy
Member #007
It is designed to keep the traction lok clutch plates from slipping excessively and glazing prematurely. The lube by itself is great for the hypoid gears and bearings but not ideal for the wet clutch pack as the lube is too slippery for the clutches...thus the friction modifier.
The friction modifier is only added to traction lok rear ends. Open rear ends don't need it.
Kerry
also used if you gat chatter out of posi unit will keep plates from sticking with causes chatter - this is a must on ford posi unit with clutches
- Thread starter
- #6
So, needed or not with my 8.8 posi rear end? No clutch to speak of, just a spring, I think.
TOM KEISER
Member # 012
You need it
Kerry & Kathy
Member #007
The spring is what preloads the clutch discs...and Tom is right. You need it.
Kerry
- Thread starter
- #9
So, why not fill the entire rear end with friction modifier instead of lube?
Kerry & Kathy
Member #007
So why are you adverse to following Ford's recommendations in the first place...???
The traction loc has two different lubrication requirements that cannot be satisfied with just one product alone. Why is that hard to understand? If one product COULD replace both...don't you think Ford would have done that years ago...and saved millions in the process?
I had a customer in the late 70's that thought he knew more about lubricants than Kawasaki did. He had a nice 75 Z1 900 four stroke that ran great....until he did an oil change and replaced the 10w40 Valvoline oil we recommended with Caster oil designed for a two stroke engine. The owner's logic was that if it worked well in a two stroke with ball bearing crankshaft..it should work well on a four stroke with roller bearing crankshaft.
200 miles later every ball bearing in the transmission and roller bearing on the crankshaft had seized. The engine required a total rebuild including replacement of the roller crank because the owner thought he was smarter than the engineers that designed, built and tested the engine.
The direction of this thread reminds be a lot of that incident.
Kerry
The traction loc has two different lubrication requirements that cannot be satisfied with just one product alone. Why is that hard to understand? If one product COULD replace both...don't you think Ford would have done that years ago...and saved millions in the process?
I had a customer in the late 70's that thought he knew more about lubricants than Kawasaki did. He had a nice 75 Z1 900 four stroke that ran great....until he did an oil change and replaced the 10w40 Valvoline oil we recommended with Caster oil designed for a two stroke engine. The owner's logic was that if it worked well in a two stroke with ball bearing crankshaft..it should work well on a four stroke with roller bearing crankshaft.
200 miles later every ball bearing in the transmission and roller bearing on the crankshaft had seized. The engine required a total rebuild including replacement of the roller crank because the owner thought he was smarter than the engineers that designed, built and tested the engine.
The direction of this thread reminds be a lot of that incident.
Kerry
- Thread starter
- #11
Kerry, got it. I just wanted to know more info, not thinking of doing it, just wanted to know more. Your and Tom's response of "you need it" didn't satisfy my question of why I needed it.
Spoke to Danny when I picked up my car and he explained it perfectly to me. He said that the clutch packs on a posi track would make noises as you all pointed out above, but mainly on turns. This would essentially "grind" off parts of the clutch without the friction modifier. The friction modifier provides a different kind of lubrication to the clutch packs than the gear lube alone and same vice versa in that the friction modifier doesn't lubricate the bearings like a gear lube can. THAT was the point of my question, not questioning what Ford recommends, trying to understand why, and your original post didn't answer that for me. Post #4 of yours explains it, just not in layman's terms that I was looking for.
Since this is a racing tech area, I thought further simplified explanation was in order in case anyone else had a similar question. Not all of us went through the apparent education that you have and sometimes your answers are over my head, so I figure they are over someone else's too. Ok? Thanks.
Spoke to Danny when I picked up my car and he explained it perfectly to me. He said that the clutch packs on a posi track would make noises as you all pointed out above, but mainly on turns. This would essentially "grind" off parts of the clutch without the friction modifier. The friction modifier provides a different kind of lubrication to the clutch packs than the gear lube alone and same vice versa in that the friction modifier doesn't lubricate the bearings like a gear lube can. THAT was the point of my question, not questioning what Ford recommends, trying to understand why, and your original post didn't answer that for me. Post #4 of yours explains it, just not in layman's terms that I was looking for.
Since this is a racing tech area, I thought further simplified explanation was in order in case anyone else had a similar question. Not all of us went through the apparent education that you have and sometimes your answers are over my head, so I figure they are over someone else's too. Ok? Thanks.
Tim it is called friction modifier for a reason and the reason is to stop the chatter cause by just normal lube ( due to not being slippery enough ) on the friction dics sticking to the steel disc in that type of posi unit. The oil from sperm whale used years ago was also very slippery and would not cause chatter, it is outlawed due to killing of the sperm whale to manufactor it.