FRPP Diff cover seal issue

[phayze]

So recently I just installed a FRPP diff cover and did MM front and rear poly bushings. Last night I was testing my new n2mb wot box and I was doing flat foot shifting when my diff seal blew. I checked it today and 1 bolt is gone, and three are backed out halfway....

I sealed the diff with gray rtv. I put a nice bead around the pumpkin and a nice bead on the cover and put the two together. I noticed some got in the bolt holes as I put the bolts in but didn't think anything of it. I hand tight all the bolts, I skipped every other as my pattern. Then came back around 30 minutes later and torqued them to 25ft-lbs. I waited 4 days because I was waiting for more parts. Plenty of time for diff to seal properly. I also tightened the two load bearing bolts or whatever they are to spec. I scraped off the excess rtv off the sides and installed it all. Filled it with 2qts of 75w-140 and it drove fine with no leaks for 3 weeks until last night.

I feel like I shouldn't have gotten any rtv in the bolt holes but I'm unsure of what would make them back out. I have ARP bolts coming in. Would a little dab of loctite hurt?

 

[KLLR SNK]

When tightening the bolts, instead of using a skipping sequence use a cross pattern to even out the pressure on the surfaces. Since you torqued the bolts to spec I wouldn't think they would come loose but weird things do happen. You might want to allow the rtv to skin before assembly then full 24 hours for the rtv to completely dry before filling with gear lube. Most torque measurements are for dry hole not wet hole specs so since the case is aluminum you could use a little blue loctite but reduce the torque to 75% or about 19ftlbs. Make sure the carrier bearing load cap bolts are torqued to 5-10ftlbs but no more. Hope this helps.

 

[351stang]

2 qts is waaaaay too much gear oil. That doesn't explain the bolts backing out.

 

[351stang]

Diff is puking oil
https://r.tapatalk.com/shareLink?ur...hare_tid=1126986&share_fid=16174&share_type=t

 

[Dave.O]

I just went through this earlier this year.
FRPP cover with MM/FTBR aluminum diff mounts, end up ripping 4 bolts out whilst road coursing. Initially the bolts would loosen, and I would constantly retighten in between session and eventually stripped entirely.
See what slowSVT did in the thread below:

http://www.svtperformance.com/forum...ld-the-strongest-irs-pumpkin-possible.949149/

Helicoil to repair damaged threads then I used grainger part# 1DY42 double thread 5/16 and had to trim approx 3/8" off one end to fit. use blue thread locker on diff end, lock washer, washer and bolt on cover side.

Gone through 3 track events since (one of which was COTA) where I beat on it and had no issues. I highly recommend this upgrade and will do this to very IRS I have going forward on initial build.