4l60e TQ and HP Question

[PlayingWithTBI]

Well, I'm learning a lot - maybe more than I want to but, keep it up Nick! I wish there was a way to economically have you look at mine. Sorry for the derail!

 

[NickTransmissions]

Well, I'm learning a lot - maybe more than I want to but, keep it up Nick! I wish there was a way to economically have you look at mine. Sorry for the derail!

If you're in Tonopah, AZ it's only a 5-6 hour drive, assuming US93 isn't jammed up somewhere, lol!

 

[L31MaxExpress]

Shearing the rear case lugs at the low reverse clutch pack is rare but can happen if the anti-clunk spring is left out and/or the rear planetary welds itself to the l/r clutch pack and the entire unified assembly repeatedly reacts against the case lugs at high RPM (high = ~2k+ in this context). Usually requires a combination of causes to bring this type of failure about, including left out clunk spring and lube failure (leaving out the viton seal in the forward drum will cause lube starvation in the rear of the case pretty quick).

The zipping noise sounds like planet pinion needle bearing failure - makes sense you'd neutral if a catastrophic planetary carrier failure occurred upon acceleration.

We did not spend a lot of time diagnosing the actual failure in that unit. It was the OEM GM transmission with 38K miles at the time and was essentially a pile of scrap after the failure. The builder that helped me build it was actually my transmission instructor when I went through an automotive trade school in the early 2000s. He was a well known performance 700r4/4L60E builder in those days, was still building them in addition to teaching, and the replacement unit had over $1000 in upgraded parts back then. He wanted to teach and I went to his shop after school and we built the thing in a couple of evenings. It had all the durability upgrades for fleet/towing or taxi type use. The core we used was a 4L65E from an Escalade that had been wrecked and had a damaged bellhousing. We coverted it to use the older 5.7 bellhousing, input shaft, stator support and torque converter and swapped the solenoids (I forget which, 3-2 downshift maybe) necessary for the older black box PCM to control it.

 

[Aidan Kesler]

If his transmission builder put together his 4L60E in keeping what @Aidan Kesler stated in his first post and the OP doesn't beat on it constantly, it should be fine with the stated HP and TQ levels. 4L65Es come from the factory built to handle between 375-450HP or so...Also, I've built more 700R4s and 4L60Es for 400-500HP DD/Cruiser/fun vehicles than I can count and haven't had one come back yet because the owner overpowered it with either the engine or his driving habits.

As much as I like the 4L80E swaps, doing that in his particular case makes no sense given he just had his trans rebuilt with the caveat the builder put it together per the intended application.

OP should be calling his builder to confirm that his trans was put together roughly similar to what I laid out above.

I will contact him tomorrow evening when I can. Learned a lot on this thread so far, thank you.

 

[Aidan Kesler]

Check your sticker for the RPO and report back. I'm guessing you've got 3.73s in there now, at least that's what Dad's '95 K1500 SCLB 5.7L was given by The General.

Examples:

You must be registered for see images attach

4.10 gears would make a nice combination with those tires and that transmission's gearing, even 4.56 if you want the engine RPM a little more into your torque band at road speed.

Let's look at a using 4.10 rear gear. On 33" tires:

- RPM at 70MPH in OD = 2047 (not bad)

- RPM at 65MPH in D = 2716 (a little low IMHO)


I think I would try to gain more advantage, so let's look at 4.56 gears:

- RPM at 70MPH in OD = 2277

- RPM at 65MPH in D = 3016 (a good range for pulling a trailer)


Of course, the gears both front and rear are affected if one wants to maintain the 4x4 functionality.

When swapping these to 4.56. Can I just do ring and pinion or do I have to worry about anything else? Can I just buy the ring and pinion set for $120 and do it on a lift in an hour or so?

 

[1998_K1500_Sub]

When swapping these to 4.56. Can I just do ring and pinion or do I have to worry about anything else? Can I just buy the ring and pinion set for $120 and do it on a lift in an hour or so?

I'll approach it this way: If you have to ask the question, then the answer is probably "No". Setting up a rear end is not a plug-n-play, bolt-on type of exercise... not if quiet operation and longevity is desired, IMHO.

See the attached from the 1998 FSM, which illustrates some of the procedures required to R&R the gears from the rear differential; the front probably involves different steps to achieve the same objectives.

Make note of at least these sections:

- Pinion Depth Adjustment
- Backlash Adjustment
- Gear Tooth Contact Pattern Check

IMHO this is a job for a person with experience.

Maybe you're that guy

 

[Aidan Kesler]

I'll approach it this way: If you have to ask the question, then the answer is probably "No". Setting up a rear end is not a plug-n-play, bolt-on type of exercise... not if quiet operation and longevity is desired, IMHO.

See the attached from the 1998 FSM, which illustrates some of the procedures required to R&R the gears from the rear differential; the front probably involves different steps to achieve the same objectives.

Make note of at least these sections:

- Pinion Depth Adjustment
- Backlash Adjustment
- Gear Tooth Contact Pattern Check

IMHO this is a job for a person with experience.

Maybe you're that guy

I understand all the adjustments and checking all that. I just mean, do I got to worry about anything like, bearings or shims, or any of that junk while I’m in there? Like a “I’m already in here so might as well do this” type deal, I’ve never personally taken one apart and rebuilt it. And IMHO, I believe the only way real experience comes, is getting your hands dirty and taking the job yourself, all things considered!

 

[1998_K1500_Sub]

I understand all the adjustments and checking all that. I just mean, do I got to worry about anything like, bearings or shims, or any of that junk while I’m in there? Like a “I’m already in here so might as well do this” type deal, I’ve never personally taken one apart and rebuilt it. And IMHO, I believe the only way real experience comes, is getting your hands dirty and taking the job yourself, all things considered!

Very well, I admire your tenacity, and I couldn't agree more

Other members should probably comment because I'm not a "rear end" guy, I've always taken mine to someone else for repairs. "Setting-up the gears", in particular, has made me shy-away from the process.

That said, there are at least four areas of focus (and maybe more):

- the bearings residing at the ends of the axle tubes and the bearing surface on the axle (the axle itself is the inner race of the bearing; the bearing's rollers and outer race are installed in the axle tube)

- the seals on the ends of the axle tubes adjacent the bearings

- the pinion bearings and seal,

- the carrier bearings


Similar areas of focus exist on the front differential as well.

In my opinion any proper work on a differential / axle would include an assessment and possible replacement of all the items above with quality parts ("quality" is something that gets a lot of discussion on GMT400).

Clearly, if you have existing noise or gear lube leakage past any of the seals, something inside the rear would benefit from the attention.

At this point I'll let others comment, as I'm outta my league.

Too, I'm sure there are many threads on rear end service. Take a look around.

 

[97c1500ext]

I understand all the adjustments and checking all that. I just mean, do I got to worry about anything like, bearings or shims, or any of that junk while I’m in there? Like a “I’m already in here so might as well do this” type deal, I’ve never personally taken one apart and rebuilt it. And IMHO, I believe the only way real experience comes, is getting your hands dirty and taking the job yourself, all things considered!

Id say best to do axel and pinion bearings and seals if you are doing a gear swap. If you haven't had it posi-ed yet that might be something to look at. Eaton-trutrac is the go to ive seen many speak well of and i myself had one installed not long ago. You will need new inner axel bearings of a non-factory size for the truetrac and most other parts needed can be bought as a kit. The factory locker is okay but does not like launching from what i understand. There really isnt much else in the rears

 

[1998_K1500_Sub]

Id say best to do axel and pinion bearings and seals if you are doing a gear swap.

A retired mechanic who I've used for rear-ends (he lives in Saginaw, MI) always gets his parts from Drive Train Specialists in Detroit ("DTS", https://www.drivetrainspecialists.com/about-us). For him, it's a 45min drive to DTS or a one-day ground shipment.

He claims their bearing sets are OE quality.

Bearing quality has been a recurring topic on GMT400.

YMMV, I'm just repeating what he told me. I literally drove to DTS from his house and picked up the parts he needed.