GM 12 bolt truetrac help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Chilly178 · Yesterday, 06:06 PM

Hi I recently rebuilt my rear axle out of my 67 C10 put in a new true trac pn 913A315 and these holley conversion axles pn 02-119. I put the axles in with the new clips. In the kit with the trutrac it gave me a steel pin and a plug with a C clip. In the diagram for the trutrac it shoes a spacer instead of a pin. Anyways when I went to put the pin in it is kinda tight going in. I could probably get it in if i tapped it with a hammer. I'm not 100 percent certain but I thought it said in the directions that is is supposed to have some axle end play. Is there supposed to be some end play?

LS short box · Yesterday, 08:47 PM

Looking for others to step in but when I did my 12 bolt with a Tru Trac I had to grind a bit off the spacer. I would check with Detroit Inc and see what they would like to see clearance wise.

**A1971Blazer** · Today, 11:39 AM

I used stock axles for mine, but the pin went in easily, along with the cover and snap ring.
Also, I don't recall checking for end play on the axles, but I'm in 800 miles and all seems to be well. It works perfectly.
You may want to pull outwardly on the axles to insure the C clip is seated fully in the side gears.

**Bob B.** · Today, 12:43 PM

Since you have a pin and not a spacer I think you would probably want to take a little off the ends of the axle shafts. Your first move is make sure the C-clips are seating as A1971Blazer suggested, and compare your new Holley axles to the stock ones. I would call Eaton to be sure.

BTW, I put a Truetrac in my '67 and couldn't be happier with it. I have a full floating Dana 60 so no issues with the shafts, no C-clips.

Chilly178 · Today, 01:50 PM

Ok so stupidly I already junked the old axles so I don't have anything to compare, but I looked at the length of the shafts and they are listed as 30 3/4" which i believe is the standard. I also tried removing the new C clips and putting in the old ones to no avail. I called Eaton and they informed me to make sure the axles are all the way out, and if not it could be two different problems/measurements. Either the butt length of the axle is too long or the groove cut for the c clip isn't wide enough. The axle end play should be around .015". I don't have a stock axle to compare it to. I'm thinking i could take some measurements when I get home, does anyone have any 67 axles laying around we could compare any differences?

Yesterday, 06:06 PM	#1
Chilly178 Registered User Join Date: May 2016 Location: Green Bay, WI Posts: 133	GM 12 bolt truetrac help Hi I recently rebuilt my rear axle out of my 67 C10 put in a new true trac pn 913A315 and these holley conversion axles pn 02-119. I put the axles in with the new clips. In the kit with the trutrac it gave me a steel pin and a plug with a C clip. In the diagram for the trutrac it shoes a spacer instead of a pin. Anyways when I went to put the pin in it is kinda tight going in. I could probably get it in if i tapped it with a hammer. I'm not 100 percent certain but I thought it said in the directions that is is supposed to have some axle end play. Is there supposed to be some end play? Attached Images Last edited by Chilly178; Today at 11:48 AM.

Yesterday, 08:47 PM	#2
LS short box Registered User Join Date: Jun 2015 Location: Carlos MN Posts: 2,028	Re: GM 12 bolt truetrac help Looking for others to step in but when I did my 12 bolt with a Tru Trac I had to grind a bit off the spacer. I would check with Detroit Inc and see what they would like to see clearance wise.

Today, 11:39 AM	#3
A1971Blazer Senior Member Join Date: Nov 2013 Location: East Tennessee Posts: 2,137	Re: GM 12 bolt truetrac help I used stock axles for mine, but the pin went in easily, along with the cover and snap ring. Also, I don't recall checking for end play on the axles, but I'm in 800 miles and all seems to be well. It works perfectly. You may want to pull outwardly on the axles to insure the C clip is seated fully in the side gears. __________________ 1967 C10 Step side 1968 C10 Step side 1970 Chevrolet K/5 Blazer 1972 Chevrolet K/5 Blazer .............

Today, 12:43 PM	#4
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,325	Re: GM 12 bolt truetrac help Since you have a pin and not a spacer I think you would probably want to take a little off the ends of the axle shafts. Your first move is make sure the C-clips are seating as A1971Blazer suggested, and compare your new Holley axles to the stock ones. I would call Eaton to be sure. BTW, I put a Truetrac in my '67 and couldn't be happier with it. I have a full floating Dana 60 so no issues with the shafts, no C-clips. __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

Today, 01:50 PM	#5
Chilly178 Registered User Join Date: May 2016 Location: Green Bay, WI Posts: 133	Re: GM 12 bolt truetrac help Ok so stupidly I already junked the old axles so I don't have anything to compare, but I looked at the length of the shafts and they are listed as 30 3/4" which i believe is the standard. I also tried removing the new C clips and putting in the old ones to no avail. I called Eaton and they informed me to make sure the axles are all the way out, and if not it could be two different problems/measurements. Either the butt length of the axle is too long or the groove cut for the c clip isn't wide enough. The axle end play should be around .015". I don't have a stock axle to compare it to. I'm thinking i could take some measurements when I get home, does anyone have any 67 axles laying around we could compare any differences? Last edited by Chilly178; Today at 02:04 PM.



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