BMW/Titan LSD Viability

[O.G.]

Having read the numerous threads previously on this subject I decided recently to have my LSD rebuilt by Road & Race. I had been concerned about the state of my Titan in a 360R (180hp). The car kit was supplied 2015, with only 3000 miles and 5 Track Days on the clock. I was worried about noises and what I thought was too much slack in the drive train.

Road and Race replaced the carbon plates for sintered although as it turned out all internals were only moderately worn. Now I have found the drive to be harsh & even more noisy when not pushing along (we cant push all the time on the road).

As an experienced engineer I find it difficult to understand why CC could not find a LSD to fit which was fit for purpose ie both on the road and track. After all LSDs are a piece of established technology in a very light weight and therefore lowish stress application.

It has cost me more than £800 pounds so far and I'm not happy with the results. I will be following this and any further threads with great interest.

O.G.

[ChrisC]

Just for reference, all Titan LSD CC supplied since 2018 (ish) have been fitted with the sintered internals.   Since you have the car on order I assume you have test driven a 420R and are aware of the noise the sintered internal make when not pushed.   If you haven't then I would advise booking a test drive to satisfy your worries.   Ensure the car you drive has a sintered LSD, and resist the temptation to put your foot down, consider driving as if you were running it in. 

As for the other important question, sintered Titan internals have only been fitted since 2018, meaning the life expectancy is unknown.  To a certain extent thats also true for the SPC diff because its also new. A comment was made earlier in this thread that the Titan was considered a wonder replacement a few years back.  BUT there is a simple test procedure outlined on this site to gauge the life of your diff.  You will be able to monitor your diff from new and thus get the maximum out of what CC supplied. 

Basically panic not.  I am in the same boat, my 420R has only been on the road since August, I will monitor my sintered Titan diff, and decided to replace or rebuild when the time comes.    In the mean time I will enjoy the car for what it is. 

[aerobod - near CYYC]

There also seems to have been a change in the carbon plate composition or manufacture at some point, as anecdotally those of us with older R400Ds seem to have had less problems with the carbon plates (mine is a 2012) than more recent cars.

[Petethediesel]

As regards the timing of sintered plate introduction, perhaps this may help.

   I ordered my kit 360 in December 2017. At that time the carbon plated LSD was standard but my order was noted that a sintered plate diff was required. I was advised, in early 2018 that sintered would likely be standard from around March 2018. 

[paul jacobs]

Given the reliability problems then, how difficult is it to change out the BMW diff completely and go back to the Ford item?

[ChrisC]

I don't think the reliability is anything to do with being BMW or Ford, so swapping to a Ford casting with a Titan LSD with carbon plates might solve nothing.   According to Titan, the plates are the same between the two units. 

[David_Long]

Ironically the issues are less prevalent on cars that are just being driven flat out on the track. In that mode the rear axle is usually locked up and the slip of the tyres allows you to corner - the plates simply lock together and don't wear. What's killing them is the slow and low torque stuff where the differential action can only be gained by slipping the plates. And that will apply to any LSD that use friction plates.

[ScottR400D]

That’s right Chris, it’s the LSD that’s the issue not the overall assembly, though the BMW housing is considerably heavier than the Ford and I know at least one member us going to swap his BMW for the Ford. 

The issues with that, assuming you can get hold of a Ford housing, are that new driveshafts and prop are needed too. 

 

[ScottR400D]

About the Titan plate composition, Phil Stewart told me that they believe there was a change in the carbon plate manufacture because early carbon LSDs lasted well. At some point around 2013/4 on, something changed and they stopped lasting and the change to sintered plates took place.  

Although the sintered plates have only been around for a few years, I believe RRT and Titan have a good idea of their longevity, gained from racing experience, hence the advice to refurb every year or 10k. 

None of that is relevant to the failure of the Bellevilles possibly, which may be another issue but could be related to the sintered plates. 

There’s a similar story with the SPC. It’s true that we don’t have a great deal of experience amongst us as users but this diff (mainly in Sierra form) has also been used in racing and on track experience cars and has shown much greater longevity as well as better performance, according to what is published and what I’ve been told. 

From my experience with my car I have no doubt it works better, but I’ve banged on about that enough. I also believe the lack of clunking, grinding and whining indicates that the diff has an easier time of things than it’s predecessor which indicates to be that it might well have a longer life. 

Time will tell. 

[CtrMint]

Well this makes an enjoyable read.

Ive got one question though, is my Titan diff likely to spit me off the road at speed, worst still into oncoming traffic!

let me add to that, how are owners supposed to know there is an issue when the diff is noisy as hell to start with.  I was given the usual response they all do that during my early road use.  I just ignore the noise now gulp

[ScottR400D]

Mark, do regular checks of the preload by the turning the wheels test and measuring the preload with a torque wrench. It’s very quick and easy to do this and I’m advised that you'll lose preload a while before anything falls apart. 

Just like CC though, I offer no warranty against consequential damage if I’m wrong....... ;)

[ChrisC]

The only failures I have heard of are basically LSD that no longer act as LSDs. 

Testing the preload at service time is what's recommended by RRT, apparently they start out with 40ft/lb preload (or maybe a bit more when new), 20ft/lb its rebuild time.  15ft/lb impending doom. 

You test one wheel off, and the other touching the ground.  The preload is the torque required to turn the hub.  I use a digital torque wrench set to record peek torque. 

 

[Wrightpayne]

Reading all these posts it does seem the Quaife ATB seems the fit and forget option for road use.

[CtrMint]

I and I suspect others would appreciate an idiots guide to such a process, would that be possible?

 

[David Brown]

A magnetic filler plug was suggested earlier in the postings. What would it pick up with carbon plates and are the sintered plates magnetic? R & R recommended a Titan diff to me around 2014. 

[DJ.]

Thanks to these threads, I have recently tested my Titan lsd preload, it is currently only 18Nm, so having spoken to Road and Race it will be removed for overhaul this winter.

I only have a Sigma125 and I'm not a particularly fast driver, but it has survived almost 8 years and 35000 miles. Donuts at Dunsfold, several Car limits days and half a dozen track days. I noticed some clunking when I fitted it and it sounds the same now. Any lsd noise is negligible compared to the whining from the (Ford) crown wheel and pinion, which unfortunately is much the same as from new.

I have three choices:

1) refit my original open diff (I had the lsd installed in a second hand old Sierra diff)

2) Have the Titan overhauled

3) Fit a Quaif ATB

4) Change to the new diff everyone is praising

I'm not going for the new plate diff as £1200 is too much. I don't fancy going back to an open diff as the car is definitely better with the Titan fitted. So it is a choice between Titan rebuild with the knowledge that I'll have to repeat in future or fit an ATB. For mainly road use, I suspect an ATB would be ok for me, so if the Titan rebuild approaches the ATB cost that's the way I will go.

Duncan

[ScottR400D]

A magnetic filler plug will pick up the inevitable bits of Bellville washer that will be flying around in there and ground off bits of the other steel parts. RRT will still recommend the Titan LSD. They'll also recommend frequent checks and rebuilds.

The parts in these images had many less than 10,000 miles on them, its fairly clear that most of the carbon has gone and the steel is being worn away and the Bellville is cracked through. My own diff was much worse, one Belleville being in several pieces, at less than 8000 miles.

[Mrp]

I have 2017 (March from factory) 420R can I tell externally what plates I have ?

Mrp

[ChrisC]

A mates factory 420R from march 2017 had carbon plates, and when I checked it a few weeks ago, it had so little preload there was no need for a torque wrench.

[ScottR400D]

Another point that dawns on me is that there seems to be some suggestion that the SPC diff is new. 

As I understand it, it’s been around for 9 or 10 years, in Sierra housing form, and has considerable history both in road, race and ‘track experience’ cars. 

It’s reliability in that form is known to that extent and is said to be excellent. The BMW is obviously slightly different in that it has to fit the 168 diff but is the same design and should be just as successful. 

 

[brianjhall31]

Well done Geoff for opening this thread.  Lots of very interesting and illuminating posts.  Now if there was an "Operator Conference" like the events I used to attend in my aerospace career.......this would be a definite agenda item!

Is there sufficient data to create a maintenance paper on this i.e. recommended service intervals, torque pass/fail criteria, overall or replace with alternative etc?

[David_Long]

That's actually a very interesting comparison to make. Reading this thread you can say (of those that have commented)  the life is about 200-300 hours. I think in aerospace terms, that that would be quite low life expectancy. Perhaps some military applications may be that low, or even lower, however in terms of a modern race engine it would be considered excellent.

I run two Titan diffs and one is scheduled for overhaul, so it may be interesting to do a detailed strip down and get some good photos for a report. And perhaps taking some of the mystery out of DIY overhauling. 

[Geoff Brown]

Brian#46: Thanks for the applause but I just had to resurrect the subject so everyone out there will realise the pain that they could go through. At Caterham's expense!

After 43 years in aviation - fixing & flying - the words 'mean time to failure' resonate for the Titan LS unit. If this was a piece of aircraft equipment it would probably have not got any further than the test bed due to early failure.

Aircraft equipment is important as otherwise the consequences are serious but with computer aided design, extensive materials knowledge, virtual testing & experience gained from physical use the Titan could have been better.

As ScottR400D #45 states the SPC LS unit has been installed in the Ford diff for many years. During an initial hard four year life it was dropped for inspection & found to be 'almost like new'. The SPC unit for the BMW diff is just a modification of the ford unit made to fit but not changed in internal spec. So one should receive the same long term serviceability. But of course changing the oil regularly, every two years? And checking the condition - dark grey/black spells danger as well as fitting a magnetic plug should see it have a long life before dropping for 'routine maintenance'.

A suitable guide to looking after a BMW/Titan unit could be produced & uploaded to the guide area of this site. All that is needed is the recommended period between servicing, how to conduct the pull off check, the wheel rotation test & any unusual noise that could be a failure marker.

All I need to do now is summon up the courage by writing letter to Caterham asking some delicate questions!!

[Wrightpayne]

Geoff,

I didn't see any recall / intervention for customers in regard to the dedion failures (shock mount) on post '96 cars albeit the design was changed and thicker wall tube used.

Sudden failure of the shock mount could launch you left or right depending which side failed.

Ian

[Geoff Brown]

Wrightpayne #49: Is this another failure by Caterham in the interests of customers ?