truetrac irs questions

[zredfire04]

hi guys, first post here. been reading a while and finally have a reason to post.

i recently (6 months ago) bought my first ever svt product, a 2004 cobra. i've been wrenching on my own ride my whole life, and i'm not gonna change that with this car.

to extend a long story, i developed an issue in my rear end. it would make a sound like i hit a pot hole, sometimes even with some bumpsteer. turns out a clutch and steel in the LSD welded together, and the slamming sound was the teeth on the side gear stripping.

i decided to replace the differential with a truetrac, as i'm not really excited by the idea of dropping the pumpkin to rebuild the LSD again.

so, now on to my actual question...do i need to use an axle spacer? there's also the plug/snap ring thing that came with it with no clear indication of whether i need to put it in there or not.

any help would be greatly appreciated.

 

[zredfire04]

i ended up calling eaton.

the answer is, yes you have to install a spacer. the plug/snap ring thing must also be used for balance, and to retain the spacer.

 

[1wild-horse]

So what did you use for a spacer? Would be kind of hard to install after the axles are in, so how did you get it in there?
I'm assuming you have an IRS yet, since you mentioned dropping the pumpkin?

I just bought a trutrac myself and the instructions say a spacer for late 05 and up mustangs.

Maybe a mod could put this in the terminator forum and it would get some attention.

 

[zredfire04]

Yes, irs. I removed the center section, aka pumpkin. You put in the spacer that's the same size as your crosspin. The plug and snap ring will keep it in place...i think. It's not possible to install with the axles in.

 

[zredfire04]

When I made the thread, I thought (mistakenly) that this section was general tech. Too bad there isn't a section like that...there's a lot of crossover from one car to another.

 

[zredfire04]

ok, so i finally dealt with the axle spacer. my trutrac came with two...one with a shallow groove and one with a deep groove. the one with the shallow groove measured .875", so it's the one i used. even with the plug installed, it is able to move around inside the carrier. i smeared some transjel on it to stick it in place. hopefully it'll stay put until i get the axles in. you could also stick the spacer to the end of one of your axles, i suppose.

 

[1wild-horse]

I should have mine built by lunch time today. Then I'm going to put the axles in with the cover off to test fit. It sure looks like that spacer is going to rattle around in there. I have seen some threads where guys are complaining of noise, clunky, rattling, grinding. Then others claim theres is totally quiet. Would be curious to know who installed a spacer and who didn't.

 

[1wild-horse]

hmm.

 

[1wild-horse]

there seems to be space for the axles to walk inward without the spacer

 

[zredfire04]

yeah, the spacer's primary role in the irs is to save the axle seals since there's no c clip to keep in place.

you're probably on to something with the noise people get from these coming from the spacer bouncing around in there. seems to me that it should be a tighter fit.

also, i'm going to have to buy a more manly pair of snap ring pliers. one set won't open big enough, and trying to squeeze the ring with the other set i have broke them LOL. time to step up my tool game i guess.

 

[P49Y-CY]

i have the instructions that came with my trutrac, and attached to it there is a color diagram of what i think might be exactly what you are talking about. i'm not too good with computers but i will try to take a picture of it and post it up.

 

[P49Y-CY]

the eaton part number for terminators' 31 spline 8.8 irs unit is 913A561.

 

[1wild-horse]

Bought mine new, so it did include the manual and a color picture of the spacer and plug. The instructions are vague at best imo. Both spacers have a groove, it says to utilize the grooved spacer for late05 and newer. The hell, which one! I'm going to use the thicker of the two as there is still some play, although less with the thicker of the two. Manual makes a mention of circlip style retainers but makes no mention of actually using a spacer for that type of axle.
So P49Y, did you put a spacer in? Think I've read a post of yours that stated yours is quiet.

 

[P49Y-CY]

Bought mine new, so it did include the manual and a color picture of the spacer and plug. The instructions are vague at best imo. Both spacers have a groove, it says to utilize the grooved spacer for late05 and newer. The hell, which one! I'm going to use the thicker of the two as there is still some play, although less with the thicker of the two. Manual makes a mention of circlip style retainers but makes no mention of actually using a spacer for that type of axle.
So P49Y, did you put a spacer in? Think I've read a post of yours that stated yours is quiet.

while i can pull a pumpkin or transmission myself and bring it to a shop, i'm not actually able to rebuild them myself (yet), so i can't really answer your question, sorry.

i brought it to a gear shop to get built and yes it does run really nice. my other car has a wavetrac (which cost me more than twice the price iirc), yet i think this trutrac performs just as well, if not better.

i agree that those instructions are vague. it looks like they were printed before this particular part number for the 8.8 irs was added.

 

[zredfire04]

yeah, the spacer with the deeper/wider groove is for 05+, i think. if used in a SRA application, the spacer is needed to keep the axles from moving inward and possibly releasing the c clips that keep them from sliding out of the carrier. on the IRS application, the spacer is just to keep the stub shaft from going in far enough to damage the seal on the center section.

the spacer is required to prevent damage in both IRS and SRA applications...although the damage if it's not used with a SRA is significantly greater.

 

[1wild-horse]

Going to bump this up since it took me some searching to even find thread, but I managed to end up with a weird noise coming from the rear of the car. I may have 500 miles on it and just a few passes at the track.
I would describe it like someone kicked the bumper as you let the clutch out and roll foward, just taking off normally.
I called Eaton as well, the guy I spoke to said to not use a spacer as the spacer is for circlip style axles (found in a solid) to keep the axles from moving in.
I have not had a chance to pull an axle and take the spacer out but, that is my plan to see if it changes the noise at all.
The only other thing I noticed while checking things out is that there is an excessive amount of driveshaft wrap. I can turn the shaft about an 1/8 of a turn before it catches up to spin the axles. When I asked about this I was told it was normal and it probably is not telated to my noise.....
So, anyone with a tru trac that can verify the slack in the driveline, and have no noises etc.? Dreading pulling it again but I will if I have to.
Btw, did go over a bunch of nuts and bolts to see if something came loose.

 

[GodStang]

I do not remember installing a spacer when I did mine back in 2012. I have a whole thread about it somewhere on here I may need to see if I can find it. I don't remember access slop in mine and I only use dino oil in it as many that use synthetic oil have noise issues.