Help diagnose a 8.8 rearend issue

[TexasBlownV8]

Sir, I believe that is a very accurate assessment of the situation.
...and a lesson why not to tighten by impact alone...

 

[05stroker]

Sir, I believe that is a very accurate assessment of the situation.
...and a lesson why not to tighten by impact alone...

Question now is, when changing a pinion yoke what should the nut be torqued to? Is there a way to do it and have the correct preload afterwards?

 

[GrnBullitt08]

IDK, I could have sworn I filled till it cam out the overflow plug but man there was a lot of fluid in there! LOL

Yeah, I usually use the finger measurement myself and check if its level with the fill hole. I re-assembled the rear end in the Bullitt a few times. First time I guestimated and used 80-90 Valvoline Synthetic with 4oz of Friction Modifier, second and third I used Ford's stated amount (4.25pts) and went with Royal Purple 75-140 minus the friction modifier. But at $18.99 per container it was definitely not wallet friendly.

Bearings were scared. The third pic is carrier bearing race. I was running dino oil.

I think the issue cam about when I swapped the pinion flange for the new DS setup after the rear had been setup and installed. I removed the fac. flange and installed the new one with an impact. I think at that time the pinion preload was compromised and was too tight.

I agree it sounds like you were over-tightend. Impacts are easier, but its hard to accurately set the pre-load without doing it by hand.

Question now is, when changing a pinion yoke what should the nut be torqued to? Is there a way to do it and have the correct preload afterwards?

I'm not sure of the exact torque spec of the nut, but i believe the pre-load for a new bearing and race setup of these 8.8s is 20-25 inch/pounds and 10-15 inch/pounds on used.

 

[GrnBullitt08]

This is the same concept I used....for visual purposes...

http://www.youtube.com/watch?v=8APYO2sZyJU

 

[tmcolegr]

Question now is, when changing a pinion yoke what should the nut be torqued to? Is there a way to do it and have the correct preload afterwards?

here's the OEM procedure

 

[05stroker]

here's the OEM procedure

Thanks!

Here is the next issue. I removed the abs reluctor rings while everything was apart so I could get a full press on the Strange bearings this time. Last time the rings where not mach. enough due to a communication issue withe the shop and the mach. shop. We were only able to get 16T on the bearings. After removing the rings I went to 20T on the press and the bearings moved slightly. Issue is now they are very close to the brake caliper mount, like .015 to .025.

What is the min. clearance you would run here?

The rotors get very hot and have to expand some.

Here is a pic., looks closer then it is but you get the idea with the measurements.

 

[skwerl]

Yeah, I usually use the finger measurement myself and check if its level with the fill hole. I re-assembled the rear end in the Bullitt a few times. First time I guestimated and used 80-90 Valvoline Synthetic with 4oz of Friction Modifier, second and third I used Ford's stated amount (4.25pts) and went with Royal Purple 75-140 minus the friction modifier. But at $18.99 per container it was definitely not wallet friendly.

I actually resealed my differential cover today and refilled with gear lube. The parts store computer said 3.75 quarts which matched my confirmation checking the level at the fill hole.

I also used synthetic last time (Mobil1) and had a bit of gear whine between 60-80 mph. Today I used Valvoline conventional 85w-140 limited slip and my gear whine is gone.

 

[TexasBlownV8]

+1 on the procedure. There's no pinion nut torque; that's what the crush sleeve is for, in getting the pinion nut tight enough to establish proper pinion pre-load.

 

[fastback]

on used pinion bearings, you would be measuring "break away" torque, if any.. rotating torque will be next to nothing .... but you must measure rotating torque before you remove the nut, of coarse thats assuming it was assembled correctly to begin with.... matco has a beam inch pound torque wrench that works great for this...

 

[05stroker]

Thanks!

Here is the next issue. I removed the abs reluctor rings while everything was apart so I could get a full press on the Strange bearings this time. Last time the rings where not mach. enough due to a communication issue withe the shop and the mach. shop. We were only able to get 16T on the bearings. After removing the rings I went to 20T on the press and the bearings moved slightly. Issue is now they are very close to the brake caliper mount, like .015 to .025.

What is the min. clearance you would run here?

The rotors get very hot and have to expand some.

Here is a pic., looks closer then it is but you get the idea with the measurements.

Well, even with the tight tolerance the brakes seem to be working fine after some testing tonight.

 

[05stroker]

Happy to report that the rear is doing well. No noises, no metal, and running smooth.

Thanks for all the help and direction on the updated parts guys!

 

[Kevinmach1]

I just ordered the kit with the high torque bearing.

Will I need to find the shim for the inner pinion bearing race, or does it come with the kit?

Here is the link for the kit I ordered...

http://www.yatesperformance.com/dt3630.html

 

[Rene06GT]

Ur correct to the cause, crush sleeve, backlash and looking at that race..... Wow, good thing you caught it. Sounds like this time ull have no issues just make sure to add friction modifier

 

[OneQwkStang]

I had my rear end rebuilt by my local dealership, diff. clutch pack TSB. Went to the track few weeks ago and hit third gear and heard a loud bang. We took the diff apart and discovered the dealership didnt even crush my crush sleeve.

 

[05stroker]

Ur correct to the cause, crush sleeve, backlash and looking at that race..... Wow, good thing you caught it. Sounds like this time ull have no issues just make sure to add friction modifier

Not with a true track.

 

[mustangmike6996]

i have seen worse races not cause a noise. and i have seen ppl slaughter a gear install, for some reason it seems like some ppl just get lucky.

as for the synthetic gear oil, i have also heard that it makes the gears whine. can anyone confirm this?

 

[P-51Sonic]

sorry for thread jacking... but im in the process of installing a new rear end on my car and i was wondering if there where any write on how to install a complete new rear end

 

[Rene06GT]

Not with a true track.

wow glad you caught that, I was thinking limited slip for some reason when I saw that.