Trans am grinding while on deacceleration ????????

**402 Guru** · 11-12-2009, 07:10 PM

so when i was almost home i hear this grinding sound comming from the rear of my car , so that night i put the car on jack stands instected the hub barings and found that they are normal , then drained the differential found a couple of metal flakes in the magnitized drain plug. i instected the ring and pinion ( Richmond 3.73 gears ). I have replaced the folowing in the past 12 months t-56 trans mission , full rebuild of the 12 bolt including bearings , full suspension front to back just not lowering springs,... ok so theres what i have done with my car now i hear the weird tapping grinding (like 2 cogs are meshing together with no oil) fron the rear of my car and its only starts when i do a shift from first to second gear then i let go of the gas peddal and the sound starts to sound it sounds like a hammer is pounding on my car and when i put it in nutral the pounding hammer starts to slow doen as the rpm go down. i also notices it is completly normal when the car is warming up but when it does happen i can feel it in my hurst shifter .. why is this happening i was under my car for 8 hours and i cant explain whats going on everyone ?if its broken i can fix it help guys!? i know someone else has has this

**402 Guru** · 11-13-2009, 11:49 AM

so i put it on jack stands agian put the tires off the ground found the driveshaft u joints were distorted and tapping the diffrential the crush collar was broken im thinking a full diffrential rebuild and new u joints .... im going to chech the forms and see if someone has a set ...

**jcws6** · 11-16-2009, 04:30 AM

In your new rebuild, I'd highly recommend a solid pinion spacer in place of a crush sleeve. Summit sells a Ratech one for about $10. Pretty cheap insurance, in case this type of thing ever happens again.

**402 Guru** · 11-16-2009, 11:12 PM

Originally Posted by jcws6

In your new rebuild, I'd highly recommend a solid pinion spacer in place of a crush sleeve. Summit sells a Ratech one for about $10. Pretty cheap insurance, in case this type of thing ever happens again.

thanks .. so dont get a crush sleve.. i took the diffrental cover apart looks like my girdle saved my 3.73 gears and there is nothing broken inside my diffrental just has a broken crush sleeve and the u joint is disfigured lookis like the guys who did my exhaust

some how my pipes moved where they were from and slamed agianst my driveshaft shaved some of the metal weights off and twisted my driveshaft u joints then made a terrable buzzing when i got off the freeway i was lucky it didnt happen when i was on the freeway

**Smittro** · 11-16-2009, 11:43 PM

Twisted U-joints? I'd have the drive shaft checked or just replace it. U-joints themselves are usually made of cast iron. They tend to break not bend/twist. I'd also check the entire drive line for damage aswell.. IMO

**402 Guru** · 11-17-2009, 12:27 AM

Originally Posted by Smittro

Twisted U-joints? I'd have the drive shaft checked or just replace it. U-joints themselves are usually made of cast iron. They tend to break not bend/twist. I'd also check the entire drive line for damage aswell.. IMO

im tearing it down asap when i get a day off work .. its twisted near the end of the u joint and rubbing on the diffrential how the hell does that happen ? when i rotate the driveshaft i can see the u joint rubbing agianst the diffrential this sucks guys

**Smittro** · 11-17-2009, 12:37 AM

Originally Posted by un17real

im tearing it down asap when i get a day off work .. its twisted near the end of the u joint and rubbing on the diffrential how the hell does that happen ? when i rotate the driveshaft i can see the u joint rubbing agianst the diffrential this sucks guys

WOW! You're lucky you make it anywhere with that kind of damage.. Little more you have been walkin' or calling for a tow.. sheesh..Good luck..

**402 Guru** · 11-17-2009, 12:42 AM

im not moving the car at this time since the 12th till i get it fixed( when this happened i turned into the nearest parking lot cut the car off and got a tow hitch called up the grandpa and pulled it home with the good old tow hitch ) all i need is a hole through my trunk next . i was readin your twin turbo buils on your link that is wicked how much time u put into it sounds like .i will keep u guys posted with the teardown and rebuild ..

**Smittro** · 11-17-2009, 12:57 AM

Originally Posted by un17real

im not moving the car at this time since the 12th till i get it fixed( when this happened i turned into the nearest parking lot cut the car off and got a tow hitch called up the grandpa and pulled it home with the good old tow hitch ) all i need is a hole through my trunk next . i was readin your twin turbo buils on your link that is wicked how much time u put into it sounds like .i will keep u guys posted with the teardown and rebuild ..

Cool, yeah I have a sh&t ton of time in my TT build, but slowly getting close to completion. Few more weeks I should have some more to add to my thread. I think I'm lining up the Camaro for a blower next. The guys here are baaaaad influances..

But yes, do keep us posted on your work. Good luck bud..

**402 Guru** · 11-20-2009, 05:55 PM

Originally Posted by Smittro

Cool, yeah I have a sh&t ton of time in my TT build, but slowly getting close to completion. Few more weeks I should have some more to add to my thread. I think I'm lining up the Camaro for a blower next. The guys here are baaaaad influances..

But yes, do keep us posted on your work. Good luck bud..

haha i see what u mean this site is Awesome and i guess im one of the more lucky ones with a Stroked 402 and my 12 bolt is intact they are garbage 2 rebuilds in the past 2 years . :bino . im geting monday off and ill take it apart then to see exactly whats going on thanks for giving me your honest opion to what was trippin me out . i do remember for some odd reason this binding sound when i would turn the when to the right like bam bam bam bam then i would drive streight and it would slowly go away but not all the way so Would that what it sounds like when the posi is going out( got my rear end assembled when i baught it) ?? i have never delt with a posi that is going out so how would i tell if its going out??? i heard of people shearing pins of there posi units could that be the sound i was hearing

**Smittro** · 11-20-2009, 07:02 PM

Originally Posted by un17real

haha i see what u mean this site is Awesome and i guess im one of the more lucky ones with a Stroked 402 and my 12 bolt is intact they are garbage 2 rebuilds in the past 2 years . :bino . im geting monday off and ill take it apart then to see exactly whats going on thanks for giving me your honest opion to what was trippin me out . i do remember for some odd reason this binding sound when i would turn the when to the right like bam bam bam bam then i would drive streight and it would slowly go away but not all the way so Would that what it sounds like when the posi is going out( got my rear end assembled when i baught it) ?? i have never delt with a posi that is going out so how would i tell if its going out??? i heard of people shearing pins of there posi units could that be the sound i was hearing

Not exactly sure with what they all will sound like when they go out. Many different factors can cause a failier. But sometimes you'll get only a one legged burn out if they are failing, kinda like a limited slip.. I've seen, teeth sheered off the ring, pinions with missing teeth, bearing fails, and so forth.. I've even seen on an older rear where the "C" clip had fallen to the bottom of the houseing and the axle come out while going down the road tire and all..

**402 Guru** · 11-20-2009, 07:16 PM

Originally Posted by Smittro

Not exactly sure with what they all will sound like when they go out. Many different factors can cause a failier. But sometimes you'll get only a one legged burn out if they are failing, kinda like a limited slip.. I've seen, teeth sheered off the ring, pinions with missing teeth, bearing fails, and so forth.. I've even seen on an older rear where the "C" clip had fallen to the bottom of the houseing and the axle come out while going down the road tire and all..

well sounds like im goin to take this garbage 12 bolt apart . from what ive seen and been reading alought of ppl are haveing problems with there 12 bolt i dont want to go 9' ford but.. its frustrating theres not really any other options

**402 Guru** · 11-22-2009, 09:59 PM

so i finally had time off work today after my full teardown of the driveshaft and differential i found that a pinion nut had completly backed off then the pinion and carrier bearings blew also found some u joint bearings the "+" ones that have some play that im going to do a full rebuild of the differential and order some new u joint bearings

time to drink some coffee and knock this out in a day . ive never replaced the bearings in a 12 bolt is it expensive to get them pressed in ?

**Smittro** · 11-22-2009, 10:02 PM

Originally Posted by 402 Guru

so i finally had time off work today after my full teardown of the driveshaft and differential i found that a pinion nut had completly backed off then the pinion and carrier bearings blew also found some u joint bearings the "+" ones that have some play that im going to do a full rebuild of the differential and order some new u joint bearings

time to drink some coffee and knock this out in a day . ive never replaced the bearings in a 12 bolt is it expensive to get them pressed in ?

Good luck..