Not sure if this belongs here or in the Aftermarket forum.

This was a mod I was hoping could wait till the spring but....

Ever since I put the 2" drop shackles on the truck theres been this bouncy feeling to the rear, almost as if the tires were egg shaped but I checked the tires and they are fine.

The plan was to install some 2 degree pinion shims(Thanks to Patman's advice) since driveline vibrations can sometimes happen after a drop. Since I no longer have my friends garage to work in since he moved I had to take it to my mechanics. After the truck was up on the lift for a few minutes we found that the pinion angle is only off by 0.5 degrees so no need for the shims. He said he would put them on but that would not solve the issue. He suggested we take the rear diff cover off and look inside, no charge for the look or fluid refill.

Good thing we checked, the spider gears were all pitted and one of the cap bearings was cracked in 3 places and had almost 3/8" of play. I asked if it would last till spring and he said it could go another 10000Kms or it could go on your drive home.

So after thinking how big a hit to the wallet this is to fix now or to fix later if it breaks while driving I said ok lets fix it.

Bye bye open diff and 3.08 gears and hello TruTrac LS and 3.73 gears.









Only thing is there was no clocking gear for the ABS so now I am without RWABS but I can live with that. Now all I need is to get a new speedo gear cuz its waaayy off. I still need to know whether I have the 7 or 8 tooth drive gear and seems the only way to check is to take it apart. I tried but I couldn't get it out. I have to go back to the mechanics on Friday to let him check over the rear diff to make sure things are still ok.

One thing I found is that when you let off the gas and coast you can hear the
rear whine. He said because its gear driven there will be some whine. I'll get more info on that next week.

 

Congrats on the gear change. I changed from 3.31:1 to 4.10:1 ratio gears in my '02 xcab. I also installed a truetrac in the rear to help with occasional off roading. From what I read in your post, Here is some advice for you.
Unless it was damaged, You should have been able to get off the old ABS exciter ring off your old carrier. It is sandwiched between the ring gear and carrier. You will have to unbolt the ring gear to get that off. The mechanics should have known this. My truetrac was machined to accept the ABS exciter ring.
Also, that whine. The gears in my truck make a slight bit of noise, but only when coasting from 43-40 mph. There was about the same amount of noise in the factory setup 3.31 gears, but at a different speed.
But I hope everything checks out good when you go back to your mechanic.

 

Thanks, I'm going to call them in the morning to see if they tossed my old carrier out yet. If not see if they can put the ABS ring back in, I wonder if with that missing its why its not setup right?

 

Congrats on your new and wise purchase....I run the same one in my truck and believe me you won't regret a penny! TOUGH AS HELL!!!!

 

I'm with wonder boy on this one....get that checked out ASAP cuz I don't believe your should be running with out that abs ring on there! The slightest mistake during installation can result in a 8.8 soup!!!!!

 

Update. I spoke with Eaton directly and they said 99.9% that the reason I've got the noise is because they used synthetic diff fluid. They said only use conventional. Was told it will make a small amount of noise when turning but other than that there should be no noise if the gears are setup properly. Also that its possible to take the exciter gear from the old rear diff and install it on the new one so the ABS will work. I called the shop today to make sure they still had my old parts, which they do, so this should be getting fixed tomorrow.

 

Nice work!!!

 

whatd that thing run ya price wise, i wanna get new gears for my 2002 4.6 bring it from 3.55NLS to a 4.10LS

 

Changing gears is a somewhat big investment but the truck will thank you for it!!!!!I paid 290$ 4 the rear end gears(4.56)
340$ 4 the front end gears(reverse cut 4.56)
300$ labour 4 the rear end
+-200$ 4 bearings and oil
+-500$ 4 labor front
+-200$ bearing and oil You do the math lol!!!

 

so just the rear (mines 2wd) would be about 5-600?

 

Closer to 800.

 

shiiiiiiiiiiiii......idk if this trucks worth that much!!! lmao

 

Update:

Took it back on Tuesday. Mechanic took it for a drive and said yeah its too loud and there is a clunk when it downshifts. Took it apart again, swapped over the exciter gear from my old carrier so now I have ABS again, put in the conventional 80w90 diff fluid and tightened things back up...what a difference now, no clunks and no noise, except if you turn a corner and get on the gas it clicks but thats normal for transferring power to the other wheel. I can now get the tires to squeal on dry pavement from a dead stop in a straight line, with the old setup I didn't get so much as a squeak. Feels like a new truck. The backlash is 0.010". Now I just need to get that new speedo gear and this mod is complete.

Total cost of parts, diff, gears, install kit, fluid(twice) ~$1100 Cdn.
Total cost of labour, $750.

 

Doing my own gear setup with 4.10 & Truetrac. This thread answered my question for the ABS ring but the statement above confused me.

Does the Truetrac come already machined to accept the the ABS ring or is that something I have to have a machine shop do? I purchased my Truetrac from Summit and I did not see an ABS specification when ordering.

Thanks, CDB

 

I believe when you order the TruTrac by year and model, If the application calls for rear ABS the unit will be already machined for it. When I ordered mine nothing was mentioned about rear ABS and it was machined for the ABS exciter ring