Diff.....

[Hoover.]

I'm looking at getting my diff rebuilt/refurbed to eliminate some drive chain "clonking" when I bury the right pedal in the carpet...... It's a GKN diff.......

what are my options regards actually getting it done ... have read some parts not available, but can these unavailable pats be made easily by an engineering shop ?

what about the gearing in the diffs... are there options there ?

Just want to see what is available, what can be/ can't be done...... and opinions

I am lead to believe the GKN is a better diff then BTR..... if I switched to BTR what is the hydro thingy and what does it do ?

Ok all a bit confused on what I am actually looking for..... a good free for all discussion would help

[chris watton]

What about ripping out the innards and replacing with a Quaife ATB LSD?

[QBee]

07799 117211
Possibly your best call would be to John Reid at Grantura Engineering. The acknowledged expert.

[v8trevster]

I've got a spare GKN diff I'd be happy to sell you - it's just gathering dust in the garage. Have sent you a message on facebook.

[Pete Mac]

Hoover. said:

I'm looking at getting my diff rebuilt/refurbed to eliminate some drive chain "clonking" when I bury the right pedal in the carpet...... It's a GKN diff.......

what are my options regards actually getting it done ... have read some parts not available, but can these unavailable pats be made easily by an engineering shop ?

what about the gearing in the diffs... are there options there ?

Just want to see what is available, what can be/ can't be done...... and opinions

I am lead to believe the GKN is a better diff then BTR..... if I switched to BTR what is the hydro thingy and what does it do ?

Ok all a bit confused on what I am actually looking for..... a good free for all discussion would help

Hey Hoover, I'm in a similar position to you. I have two Griffs, both with GKN diffs. My 'nut and bolt' rebuild is on hold right now until I get my garden project on the way, however I did start to investigate rebuilding the diff. I wanted to do it myself, however as you say spares as well as a manual are few and far between, however I still want to do it.

Firstly you need a 'spreader' to spread the casing to take the diff out of the casing. I was looking at making one up myself and then thought of using my 20 ton press to do the same job. I haven't got much further than that. I would be very interested in getting hold of/hiring one

All leads seemed to lead to John Reid, who was very helpful and offered to rebuild the diff himself for (I think) about £100, which seemed pretty reasonable but call me contrary but I still wanted to do it myself and I also wanted to powder coat the casing etc.

To be honest, providing gears are still OK, the only things to replace are bearings and oil seals as well as shimming out the shafts. Nobody seems to do a kit of parts but I would be very interested in being able to get hold of the bearings, seals and shims.

I have two manuals I can let you have copies of. One is a Maserati, the other is a Land Rover Manual, neither are the exact diff I think but it helps.

I've heard differing opinions on which diff is better but, to be honest, provided I can rebuild them satisfactorily, I don't plan to change the GKN diffs to BTR.

Not sure about gearing in the diff but I imagine, if gears are hard to get hold of, changing the gearing might be even harder but don't quote me on that.

If you can add anything more I would be interested to hear, particularly with regard to:

• Spreader tool
• Spare parts, bearings, oil seals, shims and gaskets
• Detailed manual

Hope this gets the debate going.

Pete

[bluezeeland]

Pete Mac said:

Hoover. said:

I'm looking at getting my diff rebuilt/refurbed to eliminate some drive chain "clonking" when I bury the right pedal in the carpet...... It's a GKN diff.......

what are my options regards actually getting it done ... have read some parts not available, but can these unavailable pats be made easily by an engineering shop ?

what about the gearing in the diffs... are there options there ?

Just want to see what is available, what can be/ can't be done...... and opinions

I am lead to believe the GKN is a better diff then BTR..... if I switched to BTR what is the hydro thingy and what does it do ?

Ok all a bit confused on what I am actually looking for..... a good free for all discussion would help

Hey Hoover, I'm in a similar position to you. I have two Griffs, both with GKN diffs. My 'nut and bolt' rebuild is on hold right now until I get my garden project on the way, however I did start to investigate rebuilding the diff. I wanted to do it myself, however as you say spares as well as a manual are few and far between, however I still want to do it.

Firstly you need a 'spreader' to spread the casing to take the diff out of the casing. I was looking at making one up myself and then thought of using my 20 ton press to do the same job. I haven't got much further than that. I would be very interested in getting hold of/hiring one

All leads seemed to lead to John Reid, who was very helpful and offered to rebuild the diff himself for (I think) about £100, which seemed pretty reasonable but call me contrary but I still wanted to do it myself and I also wanted to powder coat the casing etc.

To be honest, providing gears are still OK, the only things to replace are bearings and oil seals as well as shimming out the shafts. Nobody seems to do a kit of parts but I would be very interested in being able to get hold of the bearings, seals and shims.

I have two manuals I can let you have copies of. One is a Maserati, the other is a Land Rover Manual, neither are the exact diff I think but it helps.

I've heard differing opinions on which diff is better but, to be honest, provided I can rebuild them satisfactorily, I don't plan to change the GKN diffs to BTR.

Not sure about gearing in the diff but I imagine, if gears are hard to get hold of, changing the gearing might be even harder but don't quote me on that.

If you can add anything more I would be interested to hear, particularly with regard to:

• Spreader tool
• Spare parts, bearings, oil seals, shims and gaskets
• Detailed manual

Hope this gets the debate going.

Pete

re them Maserati and LR manuals, would you have a copy ?

[Pete Mac]

bluezeeland said:

re them Maserati and LR manuals, would you have a copy ?

Pm me and I will send them. Pete

[Hoover.]

I really would be interested in why people seem to think the GKN in superior to the BTR.....

[stesrg]

I am all on this one ? especially the powder coating of the casings !!
Ste .

[Barreti]

Have we got a source of replacement crown wheel and pinions for the GKN diff?
I thought these were like the proverbial rocking horse stuff and a GKN diff with damaged crown wheel and pinion is pretty much scrap.

I've still got my old GKN diff and it would be good if I could get it rebuilt as a spare.

[Sardonicus]

Barreti said:

Have we got a source of replacement crown wheel and pinions for the GKN diff?
I thought these were like the proverbial rocking horse stuff and a GKN diff with damaged crown wheel and pinion is pretty much scrap.

I've still got my old GKN diff and it would be good if I could get it rebuilt as a spare.

I have too but my s/hand unit still has a good CWP fortunately but I still have not got round to building it along with a pinion assy pre-load solid spacer my old unit is a bit weepy but as been trouble free in over 10 years and quiet (not silent) its due an oil service soon I use BMW LSD oil 75/140

Edited by Sardonicus on Tuesday 16th June 09:41

[Pete Mac]

Hoover. said:

I really would be interested in why people seem to think the GKN in superior to the BTR.....

Hoover, I wasn't aware that it was, in fact I heard that the BTR is superior to the GKN, like all things TVR it is very much a matter of opinion....! I'm staying with the GKN because I can.....! Pete

[Sardonicus]

Pete Mac said:

Hoover, I wasn't aware that it was, in fact I heard that the BTR is superior to the GKN, like all things TVR it is very much a matter of opinion....! I'm staying with the GKN because I can.....! Pete

I would tend to agree the BTR is stronger for a start with readily available spares

[Pete Mac]

Barreti said:

Have we got a source of replacement crown wheel and pinions for the GKN diff?
I thought these were like the proverbial rocking horse stuff and a GKN diff with damaged crown wheel and pinion is pretty much scrap.

I've still got my old GKN diff and it would be good if I could get it rebuilt as a spare.

I'm wondering whether it is worth contacting GKN directly to see what is and what is not now available. I'm guessing others may have done this already but might be worth a try. If it proves negative then I guess it may push some of us into the final decision of whether to move to a BTR diff. Pete

[Barreti]

Thats a bloody good idea Pete.

[Pete Mac]

Barreti said:

Thats a bloody good idea Pete.

Did it this afternoon. Not terribly optimistic. Pete

[Pete Mac]

Pete Mac said:

Did it this afternoon. Not terribly optimistic. Pete

I e-mailed a guy called Colin Mortiboys, who seems to be the spares Rep, as follows:

Colin

I am the owner of two 1995 TVR Griffith 500’s both with the GKN Differential.

I have been informed that spares are very difficult to get hold of, however, on the off-chance I thought it might be worth contacting you to see if you can help. In particular I am interested in the following:

1. A workshop manual
2. Bearings
3. Oil seals
4. Gaskets
5. Drive pinion, crown wheel etc.
6. Special Tool - Axle Spreader 131 18G C or Axle Compressor GKN 131 to remove the differential assembly from the casing
7. Anything else that might be of use

The actual differential is, I believe a Salisbury unit and I have included a few pictures, including a model number on the casing, which I believe is C12HU-010-008, which might help.

Any assistance you can give me would be gratefully received.

Regards

Peter

[stesrg]

And your reply

Pete Mac said:

I e-mailed a guy called Colin Mortiboys, who seems to be the spares Rep, as follows:

Colin

I am the owner of two 1995 TVR Griffith 500’s both with the GKN Differential.

I have been informed that spares are very difficult to get hold of, however, on the off-chance I thought it might be worth contacting you to see if you can help. In particular I am interested in the following:

1. A workshop manual
2. Bearings
3. Oil seals
4. Gaskets
5. Drive pinion, crown wheel etc.
6. Special Tool - Axle Spreader 131 18G C or Axle Compressor GKN 131 to remove the differential assembly from the casing
7. Anything else that might be of use

The actual differential is, I believe a Salisbury unit and I have included a few pictures, including a model number on the casing, which I believe is C12HU-010-008, which might help.

Any assistance you can give me would be gratefully received.

Regards

Peter

[Hoover.]

I;ve got a local garage looking to this...... I'm also going to ask them to check out what quaife can actually do

[Pete Mac]

Pete Mac said:

I e-mailed a guy called Colin Mortiboys, who seems to be the spares Rep, as follows:

Colin

I am the owner of two 1995 TVR Griffith 500’s both with the GKN Differential.

I have been informed that spares are very difficult to get hold of, however, on the off-chance I thought it might be worth contacting you to see if you can help. In particular I am interested in the following:

1. A workshop manual
2. Bearings
3. Oil seals
4. Gaskets
5. Drive pinion, crown wheel etc.
6. Special Tool - Axle Spreader 131 18G C or Axle Compressor GKN 131 to remove the differential assembly from the casing
7. Anything else that might be of use

The actual differential is, I believe a Salisbury unit and I have included a few pictures, including a model number on the casing, which I believe is C12HU-010-008, which might help.

Any assistance you can give me would be gratefully received.

Regards

Peter

Response was expected but somewhat dissapointing:


Good morning Peter,

I have circulated your email to a few other contacts I have within GKN and it appears that we are unable to assist directly with this enquiry, however, the email below may provide some possibilities.

I hope this is beneficial and you resolve this soon.

Regards

Colin Mortiboys

Sales Manager UK & Ireland | GKN Service International GmbH | GKN Land Systems
M + 44 (0)7921 942918 | T + 49 (0)2205 806243 | F + 49 (0)2205 806205
[e-mail]│www.gknlandsystems.com



From: Mark Ford
Sent: 16 June 2015 15:16
To: Andrew Porter
Subject: RE: TVR Griffith 500 - GKN Differential

I think Dana down at Electric Avenue (Birmingham) took over the Diff business from GKN, they might be able to help but I don’t have any contacts down there.

We used to supply a company called Clever Trevor who took on the TVR business but they seem to have disappeared. A quick google search unearthed these guys http://www.racetechdirect.co.uk/?gclid=Cj0KEQjwkv-... which might help.

Thanks


Mark Ford

Sales Manager UK | Global Services | GKN Land Systems
P: [phone] | M: [phone] | F: [phone]
[e-mail] | www.gknlandsystems.com

Does anybody know anything of Dana in Birmingham. I did a quick Google and it was not very helpful.

I think I am missing something here. At the moment all I am looking for is oil seals, bearings and gaskets and they must be relatively easy to get hold of - any leads?

The special 'stretcher' tool would be useful but I can experiment with my hydraulic press or alternatively have one made up. I am not sure if anyone else is interested in DIY apart from myself.

A manual with the correct bearing 'pre load' values and drive pinion settings and 'pre-load' would also be very useful. I am not sure the manuals I have have the correct values.

As for the GKN innards, unless anyone can correct me, I think they will be very difficult to obtain unless anyone has better information.

The option of replacing the GKN unit with another is always a possibility but at the moment I want to stick with the GKN units.

Pete