Noisy Diff Following refurb

[nigelj77]

I had the BTR diff from my 98 450 refurbed a few weeks ago, new bearings and seals, the company doing the work commented on it not having any backlash when it was delivered and as a result wouldnt guarantee the crownwheel and pinion but adjusted the backlash back to what it should be. I was on holiday at the time so my mate who's garage were removing then refitting it agreed they should reassmble with the previously agreed parts.

I've only driven it a couple of times since but at around 40 - 50 mph I'm detecting a grumbling wining type noise so am fearing that it should have had a crownwheel and pinion while it was apart.

Anybody had this done and if so what was the cost?

I've tried calling the place that did the refurb but cant get through, suspect they are out to lunch......

[Barreti]

They did fill it with oil didn't they?

Just checking as my diff repairer went to very great lengths to tell me mine wasn't filled.
I assume its both to save money, weight and mess for him in his workshop and give me the option to put in whatever oil I might choose.

[nigelj77]

Thanks for the reply Barretti, I wish it were that simple.....

I watched the oil go back into the diff at my mates garage, I spoke to the diff repairer, he said as it had run with zero backlash it would have worn a pattern onto the meshed gears, he suggested giving it 1000 miles and it may settle down again, if not it's going to end up around £900 all in to drop it out the car, have the gears swapped etc, great news, had it been changed at the time it would have been more like £400.......

[phazed]

Sounds like you need a new BTR diff from Central.

aren't they about £900 fitted?

[nigelj77]

I wish I'd taken that route from the start but the refurb seemed like a cheaper option.

I'd be surprised if they were as cheap as £900 fitted, i think they were £880 + £50 delivery when last listed on ebay then theres in the region of 4 or 5 hours labour to swap them over.

In hindsight the new Malaysian diffs they had would have been my best option, at least the sun is out so I can start on the 1000 miles to try to quieten it down.

[rigga]

I'm sure there was an addative that was recommended on here a while back for noisy diffs. From memory I can't recall who, possibly redline, but was from the state's.

[s p a c e m a n]

• Definitely not an expert on diffs, I normally just swap them rather than rebuild. All knowledge is 2nd hand at best

From what I understand backlash is the amount of play between the gears and you need some play to stop the gears getting stuck and eating themselves, thermal expansion etc?

Why did you have it rebuilt and how long have you had it for? From what I remember you normally get vibration when the gap is too large, as when the gap is too small it makes so much noise and feels so wrong that you don't drive more than a few hundred meters. If they reckon that you had been driving it around for ages with no gap without noticing or any consequences and they've increased the gap, I would be thinking that their initial assessment was wrong and you now have too much gap, which is what is causing the vibrations.

Feel free to tear that to shreds, because I'm always up for learning more

[SILICONEKIDOBHP]

phazed said:

Sounds like you need a new BTR diff from Central.

aren't they about £900 fitted?

That is to the penny ,the only thing i have noticed is the rear bespoke bracket bolt nearly touches the chassis . I`m wondering if it may clash .

[nigelj77]

Phazed & Siliconekid I'll enquire what central want for supply only of a diff, I saw they offered a conversion to replace the gkn diff with a btr and brackets for £1100

Spaceman, the refurb place say it had zero backlash (that may well mean almost zero) I've had the car about a year and only had the diff refurbed due to it leaking oil, it felt fine and sounded fairly quiet. They claim they adjusted the backlash to the correct level for this diff. What I believe may have happened is if it has run for a long time without the correct setting the shape of the meshed gears has altered slightly, it would be nice to think it settled back down as they suggest but I'm not that hopeful tbh.

Pretty bl**dy fed up tbh :-(

[SILICONEKIDOBHP]

nigelj77 said:

Phazed & Siliconekid I'll enquire what central want for supply only of a diff, I saw they offered a conversion to replace the gkn diff with a btr and brackets for £1100

Spaceman, the refurb place say it had zero backlash (that may well mean almost zero) I've had the car about a year and only had the diff refurbed due to it leaking oil, it felt fine and sounded fairly quiet. They claim they adjusted the backlash to the correct level for this diff. What I believe may have happened is if it has run for a long time without the correct setting the shape of the meshed gears has altered slightly, it would be nice to think it settled back down as they suggest but I'm not that hopeful tbh.

Pretty bl**dy fed up tbh :-(

Offer them £900

[portzi]

nigelj77 said:

Phazed & Siliconekid I'll enquire what central want for supply only of a diff, I saw they offered a conversion to replace the gkn diff with a btr and brackets for £1100

Spaceman, the refurb place say it had zero backlash (that may well mean almost zero) I've had the car about a year and only had the diff refurbed due to it leaking oil, it felt fine and sounded fairly quiet. They claim they adjusted the backlash to the correct level for this diff. What I believe may have happened is if it has run for a long time without the correct setting the shape of the meshed gears has altered slightly, it would be nice to think it settled back down as they suggest but I'm not that hopeful tbh.

Pretty bl**dy fed up tbh :-(

was that £1100 including fitting and VAT?.
may I ask was it an Lancashire based company that refurbished the Diff for you?

Mark

[portzi]

nigelj77 said:

Phazed & Siliconekid I'll enquire what central want for supply only of a diff, I saw they offered a conversion to replace the gkn diff with a btr and brackets for £1100

Spaceman, the refurb place say it had zero backlash (that may well mean almost zero) I've had the car about a year and only had the diff refurbed due to it leaking oil, it felt fine and sounded fairly quiet. They claim they adjusted the backlash to the correct level for this diff. What I believe may have happened is if it has run for a long time without the correct setting the shape of the meshed gears has altered slightly, it would be nice to think it settled back down as they suggest but I'm not that hopeful tbh.

Pretty bl**dy fed up tbh :-(

Please dont take this the wrong way, but is your m8 TVR savy, as they are a breed to themselves. If I lived back up North I would only really use X works, or ex factory guys who have dealt with TVR's all their life and know how particular and quirky these cars are

Mark

[nigelj77]

Portzi, not sure on the diff pricing, somebody else had made the comment, looks like £1100 + vat for the replacement of a GKN diff and looks like that excludes fitting.

The mate who did the removal and refitting isnt a TVR bloke but in fairness dropping a diff out isnt that far removed from removing a diff from any rwd independednt suspension car so I'm not overly worried.

Yes the refurb company are Lancashire based, is that a concern, I was reccommended them by somebody on here???

[wuckfitracing]

I too have had my diff reconditioned by the same guy and it is perfect I dont think you need to worry about who did it.

[portzi]

nigelj77 said:

Portzi, not sure on the diff pricing, somebody else had made the comment, looks like £1100 + vat for the replacement of a GKN diff and looks like that excludes fitting.

The mate who did the removal and refitting isnt a TVR bloke but in fairness dropping a diff out isnt that far removed from removing a diff from any rwd independednt suspension car so I'm not overly worried.

Yes the refurb company are Lancashire based, is that a concern, I was reccommended them by somebody on here???

Hello, Nigel , Colin, I have had my diff refurb also by the said gentleman close to Poulton . I am very happy with my diff too. I hope yours sorts itself out Nigel.

[SILICONEKIDOBHP]

portzi said:

Hello, Nigel , Colin, I have had my diff refurb also by the said gentleman close to Poulton . I am very happy with my diff too. I hope yours sorts itself out Nigel.

You can`t get a lot of the GKN parts ,most of the lSD`s are shot and you would not even know .

[wuckfitracing]

I would

[portzi]

SILICONEKIDOBHP said:

You can`t get a lot of the GKN parts ,most of the lSD`s are shot and you would not even know .

Daz, the gentleman doing the refurbed diffs is ex factory, and has a massive reputation in the TVR racing circles. l am 100% sure he would not let a diff leave his workshop without it being serviceable.

mark

[SILICONEKIDOBHP]

[quote=portzi]

Daz, the gentleman doing the refurbed diffs is ex factory, and has a massive reputation in the TVR racing circles. l am 100% sure he would not let a diff leave his workshop without it being serviceable.



OK ,if the LSD is shot where is he going to get it from ? The answer is he will be fitting some second hand parts ,that`s why i got rid of it .

Give John Reed a call and he will explain .

Edited by SILICONEKIDOBHP on Thursday 24th July 10:55

[Sardonicus]

SILICONEKIDOBHP said:

You can`t get a lot of the GKN parts ,most of the lSD`s are shot and you would not even know .

Curiosity really Daz how did you diagnosis a faulty LSD was it lighting up only one tyre in a straight line? who told you it was knackered?