GP5 DIFF SHIMMING

[Harriot10]

So I recently bought two GP5 diffs from JRC. I removed both from the gearbox cases and shimmed the diffs with the Mugen E0206 diff washer set. After shimming both diffs, they worked well. Now to the problem! When I put the diffs back into the gearboxes, they were both binding! So I gotta be missing something. Both were smooth in the gearcases before shimming, I've shimmed many diffs before without issues, and I even tried to add a shim on either side of the cups against the bearing. Had to walk away for a bit!

Someone give me a hint on what I'm missing! Gotta be something simple!

 

[AIan]

Make sure you didn’t fold your shims in the case cover
Did you shim the imput gear? If yes maybe it’s too tight when assembled

 

[Harriot10]

Make sure you didn’t fold your shims in the case cover
Did you shim the imput gear? If yes maybe it’s too tight when assembled

No shims on the input, wasn't any when I took them apart either. I just went back and messed with it for a second and both are binding, I'm baffled!

 

[Edough13]

No shims on the input, wasn't any when I took them apart either. I just went back and messed with it for a second and both are binding, I'm baffled!

That's odd, now did they come out of and go back into the same gearbox after you shimmed them internally and are having the problem? Or did they run smooth in the diff case they came in but are now binding in different gearboxes. I know the GP5 diffs I've got complete from Jenny's were rough I ended up having to shim opposite the ring gear with 3 shims I believe and still wasn't perfect. Also make sure you have the ring gear tightened down good as maybe it's not sitting as flush or tight as it was before you took it off.

 

[Harriot10]

That's odd, now did they come out of and go back into the same gearbox after you shimmed them internally and are having the problem? Or did they run smooth in the diff case they came in but are now binding in different gearboxes. I know the GP5 diffs I've got complete from Jenny's were rough I ended up having to shim opposite the ring gear with 3 shims I believe and still wasn't perfect. Also make sure you have the ring gear tightened down good as maybe it's not sitting as flush or tight as it was before you took it off.

Same gear boxes they came out of and I shimmed internally. Everything’s tight, it’s really odd. I’m gonna mess with them again tomorrow. Gotta be something I’m missing!

 

[Edough13]

Have you tried switching the front gearbox case part as maybe you switched them as that could cause it also. I've done it before and it's crazy how different they can be will be perfect for one diff but super tight on another.

 

[Harriot10]

Have you tried switching the front gearbox case part as maybe you switched them as that could cause it also. I've done it before and it's crazy how different they can be will be perfect for one diff but super tight on another.

I’ll give it a shot tomorrow! Thanks @Edough13

 

[Edough13]

No problem man, lol one more suggestion is switching the diffs also may have put them in the wrong gearbox than they came in

 

[Harriot10]

No problem man, lol one more suggestion is switching the diffs also may have put them in the wrong gearbox than they came in

So the only thing I see that I may of done wrong is flipped the diff in the gearbox. It was my understanding the spur always goes to the left side of gearbox. (if you're looking at the open end) When I look at the interactive exploded view of the Infraction, it's on the right! Could this be my issue?

 

[Edough13]

So the only thing I see that I may of done wrong is flipped the diff in the gearbox. It was my understanding the spur always goes to the left side of gearbox. (if you're looking at the open end) When I look at the interactive exploded view of the Infraction, it's on the right! Could this be my issue?

Yes definitely could be especially with the GP5 diffs. Sometimes you even need to shave some plastic away in the gearbox next to the bearing so they don't bind and rub on it Also usually the divot in the chassis for the diff is on the left side not sure on the Infraction though.

 

[Harriot10]

Yes definitely could be especially with the GP5 diffs. Sometimes you even need to shave some plastic away in the gearbox next to the bearing so they don't bind and rub on it Also usually the divot in the chassis for the diff is on the left side not sure on the Infraction though.

Flipper the both to the right and had to add a shim to the opposite side of the spur on one. Both are now smooth as butter. Hope the chassis will accept that!

 

[Edough13]

Hopefully that works

 

[Harriot10]

Hopefully that works

Looks like I’m good!

 

[Edough13]

Looks like I’m good!

View attachment 166357

Sweet!

 

[jondilly1974]

Yep GP5 only fit if you put the ring on the right side, or else you will need to file out the diff bulkhead to make room.

 

[Harriot10]

Think I spoke too soon! After installing the GP5 diffs, they still rubbed the chassis. Come to find out, the m2c speed chassis needed a little grinding to make the diffs work on the right side. I’ll make it work! Front modified and installed!

 

[Harriot10]

Test running now, having a hell of a time staying straight! Not sure what’s going on, but I can’t get the trim dialed in. HELLA FAST with the GP5 diffs!

 

[Edough13]

That sucks man! Might look at droop and alignment with changing stuff recently may have changed your camber or toe a little bit.

 

[Harriot10]

That sucks man! Might look at droop and alignment with changing stuff recently may have changed your camber or toe a little bit.

Na, it’s something screwy! I have camber and toe set pretty good. Trim correction after trim correction. L/R over an over. I’ll try to add a more detailed description of the problem when I get back home.

Na, it’s something screwy! I have camber and toe set pretty good. Trim correction after trim correction. L/R over an over. I’ll try to add a more detailed description of the problem when I get back home.

Bad or ok to cool with car AC after a pass??

 

[Edough13]

Na, it’s something screwy! I have camber and toe set pretty good. Trim correction after trim correction. L/R over an over. I’ll try to add a more detailed description of the problem when I get back home.

OK see and I had same issue with my stretched Typhon setup at first and I had to adjust toe in a little bit on the front and now she's running nice and straight. Also have had a rear diff pin break for the cup on one side which caused a similar issue also. But sounds the same I would pull left so adjust trim to right then would pull right. Also was weird at slower speed would pull right but making pass at higher speed would pull left I think that was when the pin broke though. But I'd try adjusting toe in just a hair up front and see if that helps as it helped tremendously for me