Jump to content

GT6 Differential


Mike T
 Share

Recommended Posts

Hi all

My GT6 (mk3 rotoflex) was making loud clunks when taking up drive. I have stripped the rear suspension out (not without issues) to investigate and worn driveshaft U/Js are the main culprit as one has a very large amount of play. The diff wasn't whining or noisy and I don't want to take it out for no reason so is there anything I can check on it whilst it is still in situ with drive shafts removed? For instance how much free movement should there be in the input flange before the output flanges move - there seems to be quite a lot but my experience of differentials is limited.

Any suggestions?

Mike

Link to comment
Share on other sites

There are 2 types of backlash on a diff. The one you are feeling will be in the actual differential gears where the shims have worn, and is not usually an issue. But how many degrees or is it a quarter turn sort of amount? If that is the only issue you may be able to get it reshimmed without a full recondition, if you can find the right person. (where are you?) but with the shafts out the diff is not too bad to drop out

What is an issue is if you get backlash between the crown wheel and the pinion. That is really subtle, and usually barely noticeable.  A tiny tiny amount, and you can only just feel it. But if no whine that is extremely unlikely

How about propshaft UJ's? Radius arms and brackets (if a bracket on the heelboard is a tad loose it sounds dreadful) and diff mountings? Or the old favourite knocking exhaust?

Link to comment
Share on other sites

I will echo Clives views 

Spot on

crown wheel basklash is without the diff stripped and a dial indicator used is barely decernable very light touchy feely if you use fingers

On the coupling 

Worn or excess clearance backlash on the diff gears (suns and planets) can be upto 1/4 turn ,  is relatively normal

Are you on wire wheel and hub  adaptor splines , notorious for clunks amd knocks 

Pete

Link to comment
Share on other sites

Thanks for the comments. Checked again tonight and I would say a little less than a 1/4 turn play. Everything feels smooth when rotated though. It does leak oil and it looks like the input shaft oil seal is the source. I think I'll drop it out, replace the bushes and take a closer look as with all the suspension out of the way it shouldn't be too hard. How difficult is it to replace the oil seals?

Mike

Link to comment
Share on other sites

As long as the diff has the castellated nut at the front (as opposed to a nylock nut) the front seal is easy. Undo nut, remove seal (a seal puller is an excellent tool for this! good for core plugs too), replace seal with decent new and torque up. If fitted with a nyloc (unlikely unless it has been fitted with a later diff) the position of the nut is VITAL so you need to count the exact number of turns it takes to get the nut off, and return to exactly the same position after. Otherwise you will alter the diff setup (this type uses a crushable spacer inside the diff, if you overtighten the nut it will just keep turning, crushing the spacer and then you WILL need a specialist to strip/set it up again)

I did ask where you were. We have a local chappie is sussex who could re-shim the diff to take up the backlash, in fact Marcus on here car do it too, he is Cumbria but not on the forum often. Canley classics may be able to help too, plus anybody who rebuilds diffs should have the knowledge/skills to do it. If the diff is not making any other noises then I very much doubt it needs any further attention.

 

Link to comment
Share on other sites

Mike Papworth will I am certain be at the Triumph and MG Spares Day a week on Sunday - could save postage taking the unit there and speak with his team direct.

Not withstanding that, it's a great day out.

Clive - Mike says he is just south of Birmingham.......................................... just down the road from the show !!!!

Regards.

Richard.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...