13 replies to this topic

[Magna-Flash]

Hi!
If I jack the front up and turn one wheel there is about 3 inches (10" wheels) of free play until the other wheel "hooks up" and starts turning the other way!
There is a slight "clonk" when going on/off throttle (like worn engine mounts - but they are fine, just checked).
I suppose the "clonk" has to do with the play on the shafts - but, is it dangerous and what should be done??? Or is 3 inches OK?

regards
Magnus (SWEDEN)

[Ethel]

That does sound excessive, but it could equally be a driveshaft joint.

You could improvise some pointers to stick on the pot joints to try & narrow down where the play is.
Oh, 'n try sticking it in 4th. - to eliminate any slack in the gearbox.

[Magna-Flash]

That does sound excessive, but it could equally be a driveshaft joint.

You could improvise some pointers to stick on the pot joints to try & narrow down where the play is.
Oh, 'n try sticking it in 4th. - to eliminate any slack in the gearbox.

Great! I´ll try narrowing it down... great tip on the 4th gear - didn´t think of that!
I´ll get back with some results...

[Magna-Flash]

I´ve just been under the car and came up with this:

Total play (measured at outer part of tire) is 2 inches. Like 5 minutes if the wheel is a 60 min clock
A bit more than 1 of them inches is in the inner pot joints - the rest seem to be somewhere in the gearbox!
So about 1 inch play (measured at outer part of tire) in the diff or gears then...

Is that bad?

[xrocketengineer]

Here is my new Guess-works gearbox. It is in reverse, but it is as close to brand new gearbox as you are going to get. Sounds like Darth Vader was doing the check

Edited by xrocketengineer, 16 August 2012 - 07:46 PM.

[Magna-Flash]

Here is my new Guess-works gearbox. It is in reverse, but it is as close to brand new gearbox as you are going to get. Darth Vader was doing the check

Oh! Then I guess mine´s not that bad! Seems a little "stiffer" than mine, but - mine´s 40 years old and untouched!
Maybe it´s the pot joints then - changed the gaiters on them last winter and all the balls fell out so they are probably not in their original position.

Thanks - and may the force be with you!

/Magnus (SWEDEN)

[Magna-Flash]

Been testing again and I do think my diff is badly worn.
This is with 3rd gear - only one side lifted.
There is little or no play in the joints.
How bad is this?

[Vipernoir]

2-3" on the outside of the wheel is only 12° of rotation and I'd say well within normal limits of play in the diff and gearbox - especially after seeing your video.

Don't forget, you are not just testing the backlash in the diff, but also the entire drivetrain back through the gearbox to the flywheel.

Edited by Vipernoir, 14 April 2013 - 01:47 PM.

[xrocketengineer]

It might be even more significant the looseness in and out of the pot joint. My pot joint would slide out about 1/4 of inch and I could push it back in. I tought it was a bad circlip, but I was wrong.
Then this happened:

[Magna-Flash]

Ok, everybody - now I´m a little confused here?!
Is it normal OR will my diff look like xrocketengineers in a few days?
There is a clonk on deceleration/acceleration...

[xrocketengineer]

Ok, everybody - now I´m a little confused here?!
Is it normal OR will my diff look like xrocketengineers in a few days?
There is a clonk on deceleration/acceleration...

I had a clunk too but the bulkhead bracket of the upper steady bar was ripped out. However, if yours is 40 years old I would plan on replacing at least the pin.

[Cooperman]

It does look slightly excessive, but not unduly so. It is probably just the free play caused as the entire transmission wears. If an 'engine-out' is planned, say to refresh the bearings, clutch, oil pump, etc., then it would be an ideal opportunity to change the pin & planet wheels and check everything else.

[Gulfclubby]

I would also replace the inner pot joints if you're going to rebuild anything. If the balls fall out, the joint is worn, and they're not expensive to replace.

[Magna-Flash]

It does look slightly excessive, but not unduly so. It is probably just the free play caused as the entire transmission wears. If an 'engine-out' is planned, say to refresh the bearings, clutch, oil pump, etc., then it would be an ideal opportunity to change the pin & planet wheels and check everything else.

OK, thanks!
I will drive the car this summer as it is - if the diffs fails, so be it... ( I do infact have a spare box laying around in the garage if the housing is damaged)
Next winter it will be engine out for a major overhaul then (rings, bearings, clutch, oil pump + gearbox then ). It´s burning a lot of oil aswell...

I would also replace the inner pot joints if you're going to rebuild anything. If the balls fall out, the joint is worn, and they're not expensive to replace.

I´ve got them already in my garage since I thought they were the cause of the clonk and clunk