loud unkown clunk or pop after towing. front axle?

[williscr3]

seem to have broke something but cant find the culprit. A little background info, still in process of building my truck 96 k1500 but its still a daily driver. running 33x12.50x16 tires. truck is powered by a cammed lm7 5.3 with headers and full exhaust, tuned for above mods. stock 4l60e from 99 tahoe classic and stock drivetrain. air bags in back and cranked front 2" 3.42 gears in stock axles, 10 bolt in back along with fiberglass cap.

was backing my boat into driveway which is a little tricky and up hill. boat and gear around 4000lbs, need 4wd cause of ditch i have to get though but mostly concrete. heard loud bang. front wheels were turned a good bit, but thought 10 bolt or u joint. checked u joints, nothing... finished backing into place unhooked. test drove truck and under acceleration it would bang and grind. jacked up rear, spun tires checked u joints. i dont see anything broken. maybe i broke pinion gears or something. cant get cover off cause all 10 bolts are rusted and mis shapen. screw it... bought a 14 bolt SF with 4.10's. finally finished 14 bolt today. so now i have 1 new u joint adapting 14 bolt 1350 to my aluminum driveshafts 1330. test drive and under acceleration still hear like a loud popping noise. no more grinding but still bang bang bang under hard acceleration.

ok... maybe front axle shaft broke too from being in 4wd and turning on concrete? lifted each front tire and spun them no noises and no slop in axle shafts. maybe i did something to a front axle shaft? it was in 4wd on concrete. thoughts? is there a better way to test front shafts or axle?

did my transfercase explode? no cracks in case, still works, still engages in 4wd, no leaks under the truck. transmission mount looks fine, engine mounts look fine.

i cant figure out where its coming from and i need some methods of testing front axle shafts, housing, transfercase or maybe its my transmission? transmission seems to shift through all gears fine though.

with original 10 bolt in, i raised back end on jack stands and popped it in drive. i heard no noises.

sorry its lengthy... but any help, thoughts or input would be appreciated. thanks

 

[alpinecrick]

ok... maybe front axle shaft broke too from being in 4wd and turning on concrete?

Most likely hurt a CV joint in the CV axles--although it could be in the T-case. Turning on concrete is bad ju-ju in a truck, and the longer the wheelbase the harder on the drivetrain it will be. Install a switch that shuts off the acuator, and then can use low range in 2wd.

 

[thinger2]

You could have a bad cv joint and not be able to tell when its on a jack stand because the suspension is at full drop and the axle angle is different.
If it doesnt do it with all the weight off but it does it on the ground I would really suspect a cv problem.

 

[williscr3]

I'll revisit the front end today. Inspect axle shafts better. I didnt see any tears in boots or anything. Found some other info of clunking sound coming from rear driveshaft slip yoke binding up. Ill apply some grease to that and see what happens. Wonder if the cv axle was at such an angle that it popped its joint briefly. I used the 4wd to get out of the ditch then put back in 2wd. Had to pull forward again. Stuck in ditch again, back in 4wd then forgot that I put it in. Cranked wheel all the way to get boat straight and bang bang. Straight axle or 2500 ifs. I need to match the 4.10's in the rear anyway. Was hoping to get through the summer till it cooled down then attack the front end.

 

[454cid]

I need to match the 4.10's in the rear anyway. Was hoping to get through the summer till it cooled down then attack the front end.

You don't have matching gears now?

 

[thinger2]

[QUOTE="williscr3] I need to match the 4.10's in the rear anyway. Was hoping to get through the summer till it cooled down then attack the front end.

You don't have matching gears now?[/QUOTE]
I was kinda wondering about that myself.
Pretty much a sure fire way to shred any 4 wheel drive especially on pavement and turning too?
Multiple layers of cringe.
Let's hope he gets out of it with just an axle.

L

 

[454cid]

Re-reading a bit.... it sounds like he got the 4.10's in the new rear axle post damage.

 

[mattillac]

"...i need some methods of testing front axle shafts..."

My first thought would be to park it in 4wd, then jack up one wheel in the front via the lower control arm and attempt to rotate that wheel by hand (forward and back) and check for play/clunks/movement in the axle shafts and or driveshafts.

I would check both sides that way.

Not that I have ever tried it, just a thought.

Maybe there is a more professional way ?

 

[Ben Burrage]

Pull the drive shaft, put some good grease around the slip yoke then reinstall. See if that makes clunking go away. Dorman makes a replacement yoke that eliminates the noise.

 

[williscr3]

quick update,
the 4.10s are an after carnage. so no... i do not at the moment have matching gears nor am i dumb enough to drive with unmatched gears. at the time of the break i had matching 3.42 gears with 33" tires. this was and is a pre-plan. based on change this axle now and swap a dana 44 in, this fall when the weather is cooler. i have a dana 44 in the works out of 3/4 ton as of couple weeks ago but got side tracked with this issue. so on to the update.

greased the slip yoke, no change. was thinking same thing put it in 4wd jack up each wheel and rock each wheel. no problems in axle shafts. so either transfer case or front differential are at fault i would think? like i said the transmission shifts fine through all gears while driving. so yesterday i tossed in a spare transfercase. i didnt have any fluid laying around to fill transfercase and didnt have any time to go to store today. wife had plans of having family over and me doing yard work. tomorrow ill grab some fluid and see where this goes. ill update tomorrow. thanks for the input, all ideas and input are always welcome.