Increasing backlash in the tranny / rear-end?

[Xcessiv]

Ok guys... I recently bought a '01 GT with only 15 000 miles. It ran pretty tight. There was some minor backlash in 4th/5th, but other than that everything was perfect

I then made about 25 runs at the dragstrip on ET Streets.

The result? Some really noticeable backlash in any gear, even when launching in first gear. It sounds like a bad clutch or bad rear end... Something is sure, it wasn't as loose before. The car is driveable if I'm smooth on the clutch but I just don't like the feeling. What's the first cause of this problem on our cars?

 

[Xcessiv]

Up to the top!

 

[mustang70]

It sounds like you need to get under the car and find out where the play is coming from. The first thing I would check would be the u-joints on the driveshaft. Then check the rear end for play and then the tranny.

 

[Xcessiv]

It sounds like you need to get under the car and find out where the play is coming from. The first thing I would check would be the u-joints on the driveshaft. Then check the rear end for play and then the tranny.

I can check the u-joints by playing with the driveshaft? The play is ok.

The backlash is coming from the differential. I played with the wheel and I hear this somewhat loud "clunk clunk" which wasn't there before. What can cause backlash in the differential? It's REALLY noticeable, especially when launching from a standing start. Durain the first meter or so, it feels like there's something loose and I hear this small "clunk". Can the 4.10 backlash deadjust over time?

Your help would be really appreciated.

 

[Mike97gt]

I can check the u-joints by playing with the driveshaft? The play is ok.

The backlash is coming from the differential. I played with the wheel and I hear this somewhat loud "clunk clunk" which wasn't there before. What can cause backlash in the differential? It's REALLY noticeable, especially when launching from a standing start. Durain the first meter or so, it feels like there's something loose and I hear this small "clunk". Can the 4.10 backlash deadjust over time?

Your help would be really appreciated.

ok you need too do some more diag NOW.

it sounds like gears were done and obviously not done right.

start by seeing if you can move the pinion flange up and down if there is any play your pinion came loose.

if it's not comeing from there then you have issues in the diff. some 8.8 t-lok diffs can develop play.

if this is the issue get a new carrier and if you also have play in the pinion then you need too redo the pinion bearings.

remember when doing and differental work you need too measure your pinion depth ( if the pinion was removed) and you need too measure your backlash.

many people install new gears and don't measure. this is just HACK and will lead too failure unless you are really lucky.

 

[Xcessiv]

OUCH... In any case it's gonne get expensive.

Thanks for the info. I'll bring the car to a specialist.

 

[Torinalth]

heres a question. i am having about the same thing though not quite as severe, stock driveline all the way back.

you mentioned the T-lock can develope play, and the transmition as well. well i havnt jacked up the car and tried the wheels, but i can get the driveshaft to rotate about 1/2 inch or so before its stopped. thoughts?

thinking about the differential, the driveshaft connects to another piece at the universal joint... what is this piece and what is it connected to? the U joint is tight but there is still play in that area. would replacing the diff with an eaton and new ring and pinion be replacing everything on the inside? dont really wanna tear it apart just to see then have to refill...

Torinalth

 

[streetstang03]

dont rule out the clutch packs.

 

[Xcessiv]

Today, I inspected my car on a lifth and everything is rock solid in the tranny and drive shaft. The backlash in the differential increased by a good margin since I bought the car.

The car was already 4.10 geared and there was noticeable whine in 4th / 5th even when I bought it. I guess the car didn't appreciate the runs on ET Streets!

Two questions:
1) Is it adjustable or if everything is screwed inside?
2) How much time / money does it usually require to solve this excessive backlash?

 

[Xcessiv]

Ttt.