GT6 Mk3 Rotoflex Diff removal

[LMC]

Hi there,

 

Very long time since I have posted anything on here.

 

I need to remove the diff from the GT6 as it is leaking like a sieve and probably needs a rebuild, well it failed the MOT last year to binding brakes and its not the brakes.

 

So, if I put the car up on ramps, can I just unbolt the prop and drive shafts then the six bolts holding the diff to the spring and drop the diff out? (I am sure there are another couple of bolts holding it to the chassis)

 

Its the ramps bit which is important as I want to avoid axle stands and the spring lifter.

 

And on another note, is Mike Papworth still the best person to get diffs rebuilt by or is there someone in the South East on England who can do a decent job?

 

All the best

 

Laurie

[Steve C]

Hi Laurie

 

If it is just leaking oil, the pinion shaft oil seal can be changed in situ, although frankly it is almost worth paying a garage to do it, because it is a lot easier and safer on an overhead lift to apply the required force to undo the nut securing the input flange, and everything is a easier standing up!

 

I believe the output shaft seals (117952 on the parts manual) can also be done in situ, although I have never tried it. These are secured with allen socket screws, so no brute force needed, just a fiddle behind the flanges to get at them.

 

If your diff is actually making a racket and ready for changing, then yes, you can do it with ramps, although they will limit your access from the sides. When I swapped mine out for a 3.89 on the herald, the biggest pain was (a) having to get the exhaust out of the way and ( the two rear mountings on the diff case, which required some immoral brute force with a big bar to get them lined up so that the bolts would pass through on re-assembly. Again, all so much easier on a lift with a trans jack to support things, instead of having to provide all the strength from your shoulders while lying on concrete. The aches and pains wore off after a couple of days and some Ibuprofen...

 

Bon chance! (as they say in France)

 

Steve C

[Clive]

Rotoflex makes everything rather trickier. I can't remember the exact procedure, but I seem to remember a spring-lifter being involved and a lot of grunting.

(I have CV's on my car thesedays, nice and simple!)

 

Re brakes, rotoflex is again funny to set up, as the handbrake gets tensioned as you put the car down on the floor. The cable needs adjusting with the car at normal ride height, not full droop.

[Gary Flinn]

If you undo the Nuts/Studs that hold the Spring to the Diff on a Rotoflex car the Spring will be under tension still and get Wedged under the rear body!

 

You maybe better removing each side completely but you will need a spring lifting tool. 

 

Any work on the Rotoflex Rear Suspension is normally a Pain In the A**e

 

Never dealt with Mike Personally but he's got a good reputation and been in to Triumphs for years?

[AidanT]

Mike is still the Guy you need for Gearboxes overdrives and diffs. Was at his place about 10 months ago now and Hes a very busy guy so persist if you are trying to get hold of him

 

Aidan

[Alan C]

Laurie

 

I've recently gone through the pain of a full rotoflex suspension rebuild without a spring lifter.

Considering the tension that's involved, disconnecting the drive shafts would only be the start your problems. I would reckon that trying to realign the flanges to the diff would be well nigh impossible.

Removing the drive shafts and transverse Spring seems like your only option.

You don't need a spring lifter to Complete the reassembly though. I used a crowbar with two d shackles around the spring and an axle stand to maintain the spring at it's maximum height. You'll know when this is reached because after that the whole car starts to lift. Raise the hub assembly with a jack and place a block of wood on top of the rotoflex coupling. This acts as a fulcrum point when the block contacts with the spring and pivots the outer drive shaft up to meet the spring eye. It lines up every time without a fuss.

 

Good luck

 

Alan

[Mick]

Hi Laurie,

 

In the past I've had a Spitfire overdrive gearbox and diff overhauled by Hardy Engineering in Leatherhead, Surrey, but it depends where you are in South East England.

https://www.hardyengineering.co.uk/.

 

More recently in the past couple of months they've overhauled my Salisbury Limited Slip Diff axle. 

They know what they are doing and I would recommend them.

 

Mick C

[trigolf]

Hi Laurie,

 

Altho' you want to use ramps,rather than axle stands like me, have a look at my method posted previously further back in this section.BTW we had both posted in the wrong section technically - should be rear axle - not gearboxes !    

[TomL]

Hi Laurie,

 

Nice idea but I don't believe you'd be able to remove and replace the diff in the way you describe.  The only way for us home-mechanics is, in my opinion (as others have suggested), to remove both half-shafts, disconnect the prop shaft (obviously) and remove the spring from on top.  You can then remove the diff from below.  You won't be able to use ramps; it's an aisle-stand job.  A spring-lifting tool makes it all very much easier both for disassembly and reassembly.  My local area used to have a spring-lifting tool that it lent out to members.  You might try your local area, as someone might have one you could borrow,

 

Let us know how you get on.

 

Regards,

Tom