Broken Teeth - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dion · 11-06-2002, 08:04 PM

Well we got the gears out and guess what, they wern't 4.10, they were 3.54 The first or second owner must have changed them. I'm thinking about going with 3.31
Once everything was completely taken out we found that over the years of bad U Joints and Carrier Bearing plus blowing the gears at 80mph there was a lot of internal damage so I had to get an entire new rear.
The fun never ends.

Hooter · 11-06-2002, 09:56 PM

thats just the romance of an old pickup, always something to be done to it

WORNBRAKES · 11-06-2002, 11:05 PM

You are scaring me. I will be changing my u-joints and carrier every year now. Good luck with the new rear, I hope you are on the road soon.
Mario

Ratpowerd67 · 11-06-2002, 11:05 PM

looks like who ever did the install didnt set the gears right.

1971LT1SWBPOSI373 · 11-06-2002, 11:58 PM

I agree with Ratpowerd67, that rear end wasn't set up right. U-joints and carrier bearings won't do that kind of damage. Something wasn't setup correctly, shimming, preload or backlash, and that'll chew the gears up everytime. Were you getting any rear end noise????

dion · 11-07-2002, 12:08 AM

No noise at all, just a "Klunk" when I put it into reverse which I figured was the U Joints.
She was running great up until two weeks ago. I could get off the line like a bat out of hell and would do 100mph easy.
I just don't get it!!! I thought Dana 60's were bullet proof. I guess it's an easy guess that the gears wern't set right to begin with but I never had any problems, oh well, at least something positive will come out of this with a new rear end and 3.31 gears.

1971LT1SWBPOSI373 · 11-07-2002, 01:07 AM

Most of the time you'll get some sort of noise, which could be mistaken as tire noise or a whining sound (if you have big tires). That's just a warning shot over the bow..... a clunking sound could be a u-joint, but by the looks of that picture it was probably the backlash. Most rear ends are bullet proof and will run for several hundred thousand miles even with abuse. But if they aren't set up right they don' t last very long at all. It's not uncommon to listen to a story about a completely rebuilt rear end... and after a few hundred miles of driving the owner is on his hands and knee's looking at a hole on his differential cover where the ring gear departed. If the setup was somewhat close.... it may have ran longer in your case, for thousands of miles. That's an awesome picture though. I assume it probably punched a hole????

1971LT1SWBPOSI373 · 11-07-2002, 01:09 AM

Hey I happen to be in San Diego tonight too, on Hotel Circle South by the airport!!!!!

dion · 11-07-2002, 12:20 PM

It didn't go all the way through but it made a big dent. I didn't notice it at first but then the paint flaked off and I saw the damage. The man who is helping me restore the truck told me he's never seen that happen before in 20 years. I agree with the idea that the gears wern't put in right.

1971LT1SWBPOSI373 · 11-07-2002, 12:37 PM

It doesn't happen very often DION because alot of times there's just no reason to mess with a rear end to start with, they never go bad. They are virtually bullet proof from the start as long as you keep grease in them. But if you change the gears (and a lot of people like to do that, me included) it is absolutely essential that the alignment (pinion depth), meshing (backlash), and preload (torquing) be correct. If it's not, it starts eating itself up, and not long it spits it all out the back cover. I'm just glad to hear nothing else happend going at that speed, it could have been worse ya know!!!

Good luck with the new diff. Stop right away if you hear any noise!!! TJ

**COBALT** · 11-07-2002, 01:34 PM

While you have that driveline out I'd check your th350 for excessive output shaft play. Problems like this have a tendancy to affect the entire driveline. Since you went through U-joints and support bearings you may have caused some wear on one of your planetary/sun assemblies. What did the transmission pan have in it the last time you checked?

dion · 11-07-2002, 02:05 PM

The Tranny was rebuilt not too long ago and the last time I took the pan off evrything was fine but I'll without a doubt give it a once over, thanks.

1971LT1SWBPOSI373 · 11-07-2002, 02:25 PM

That'sreally a pretty truck you have there DION. I just looked at your photo album. Nice machine!!!!!!!!

BobbyK · 11-07-2002, 09:43 PM

Ya...I got a problem with my teeth too!LOL

dion · 11-07-2002, 10:00 PM

Yeah, that's pretty much what they looked like.

11-06-2002, 08:04 PM	#1
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	Broken Teeth Well we got the gears out and guess what, they wern't 4.10, they were 3.54 The first or second owner must have changed them. I'm thinking about going with 3.31 Once everything was completely taken out we found that over the years of bad U Joints and Carrier Bearing plus blowing the gears at 80mph there was a lot of internal damage so I had to get an entire new rear. The fun never ends. Attached Images __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

11-06-2002, 09:56 PM	#2
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	thats just the romance of an old pickup, always something to be done to it __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

11-06-2002, 11:05 PM	#3
WORNBRAKES Senior Member Join Date: Jul 2001 Location: Hughesville, MD Posts: 1,350	You are scaring me. I will be changing my u-joints and carrier every year now. Good luck with the new rear, I hope you are on the road soon. Mario __________________ Mario and Mandy Hughesville, MD 20637 69 C10 305/350 71 K5 Basket case 75 K10 Rescue Parting out 77 MG Midget Parting out 15 6.7L Cummins

11-06-2002, 11:58 PM	#5
1971LT1SWBPOSI373 Registered User Join Date: Mar 2002 Location: Springfield, VA Posts: 460	I agree with Ratpowerd67, that rear end wasn't set up right. U-joints and carrier bearings won't do that kind of damage. Something wasn't setup correctly, shimming, preload or backlash, and that'll chew the gears up everytime. Were you getting any rear end noise???? __________________ 1971 Shortbed 350/350 w/ Posi-traction 3:73's 1996 Chevy Silverado TJ in Springfield, Virginia Likes old Chevy trucks Drinks Miller MGD

11-07-2002, 12:08 AM	#6
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	No noise at all, just a "Klunk" when I put it into reverse which I figured was the U Joints. She was running great up until two weeks ago. I could get off the line like a bat out of hell and would do 100mph easy. I just don't get it!!! I thought Dana 60's were bullet proof. I guess it's an easy guess that the gears wern't set right to begin with but I never had any problems, oh well, at least something positive will come out of this with a new rear end and 3.31 gears. __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

11-06-2002, 11:05 PM	#4
Ratpowerd67 Registered User Join Date: Aug 2002 Location: Trenton ,Texas Posts: 328	looks like who ever did the install didnt set the gears right.

11-07-2002, 01:07 AM	#7
1971LT1SWBPOSI373 Registered User Join Date: Mar 2002 Location: Springfield, VA Posts: 460	Most of the time you'll get some sort of noise, which could be mistaken as tire noise or a whining sound (if you have big tires). That's just a warning shot over the bow..... a clunking sound could be a u-joint, but by the looks of that picture it was probably the backlash. Most rear ends are bullet proof and will run for several hundred thousand miles even with abuse. But if they aren't set up right they don' t last very long at all. It's not uncommon to listen to a story about a completely rebuilt rear end... and after a few hundred miles of driving the owner is on his hands and knee's looking at a hole on his differential cover where the ring gear departed. If the setup was somewhat close.... it may have ran longer in your case, for thousands of miles. That's an awesome picture though. I assume it probably punched a hole???? __________________ 1971 Shortbed 350/350 w/ Posi-traction 3:73's 1996 Chevy Silverado TJ in Springfield, Virginia Likes old Chevy trucks Drinks Miller MGD

11-07-2002, 01:09 AM	#8
1971LT1SWBPOSI373 Registered User Join Date: Mar 2002 Location: Springfield, VA Posts: 460	Hey I happen to be in San Diego tonight too, on Hotel Circle South by the airport!!!!! __________________ 1971 Shortbed 350/350 w/ Posi-traction 3:73's 1996 Chevy Silverado TJ in Springfield, Virginia Likes old Chevy trucks Drinks Miller MGD

11-07-2002, 12:20 PM	#9
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	It didn't go all the way through but it made a big dent. I didn't notice it at first but then the paint flaked off and I saw the damage. The man who is helping me restore the truck told me he's never seen that happen before in 20 years. I agree with the idea that the gears wern't put in right. __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

11-07-2002, 12:37 PM	#10
1971LT1SWBPOSI373 Registered User Join Date: Mar 2002 Location: Springfield, VA Posts: 460	It doesn't happen very often DION because alot of times there's just no reason to mess with a rear end to start with, they never go bad. They are virtually bullet proof from the start as long as you keep grease in them. But if you change the gears (and a lot of people like to do that, me included) it is absolutely essential that the alignment (pinion depth), meshing (backlash), and preload (torquing) be correct. If it's not, it starts eating itself up, and not long it spits it all out the back cover. I'm just glad to hear nothing else happend going at that speed, it could have been worse ya know!!! Good luck with the new diff. Stop right away if you hear any noise!!! TJ __________________ 1971 Shortbed 350/350 w/ Posi-traction 3:73's 1996 Chevy Silverado TJ in Springfield, Virginia Likes old Chevy trucks Drinks Miller MGD

11-07-2002, 01:34 PM	#11
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Check your transmission. While you have that driveline out I'd check your th350 for excessive output shaft play. Problems like this have a tendancy to affect the entire driveline. Since you went through U-joints and support bearings you may have caused some wear on one of your planetary/sun assemblies. What did the transmission pan have in it the last time you checked? __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

11-07-2002, 02:05 PM	#12
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	The Tranny was rebuilt not too long ago and the last time I took the pan off evrything was fine but I'll without a doubt give it a once over, thanks. __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

11-07-2002, 02:25 PM	#13
1971LT1SWBPOSI373 Registered User Join Date: Mar 2002 Location: Springfield, VA Posts: 460	That'sreally a pretty truck you have there DION. I just looked at your photo album. Nice machine!!!!!!!! __________________ 1971 Shortbed 350/350 w/ Posi-traction 3:73's 1996 Chevy Silverado TJ in Springfield, Virginia Likes old Chevy trucks Drinks Miller MGD

11-07-2002, 09:43 PM	#14
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,772	Ya...I got a problem with my teeth too!LOL __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE

11-07-2002, 10:00 PM	#15
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	Yeah, that's pretty much what they looked like. __________________ Burnout Idle 1972Cheyenne 1966/67Stouts



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