BMW/Titan LSD Viability

[CtrMint]

I was thinking of putting the RR oil in.  Pete recommended it months back, I just not had chance to sort the order.  

[Garth]

I have a 5 year old fully refurbished Titan LSD I was hoping to sell!! Not sure anyone is going to want it now!! 

[Wrightpayne]

I usually jack the rear up each side on the outer A frame point, stick a bit of 9x2 timber under each tyre then jack up off the diff.

Takes an extra couple of minutes.

Ian

[ScottR400D]

#226 Mark, my Titan was running on the RR oil when I made the recording I linked to the other day. 

After they I tried it with 75/140 synthetic which was just the same so it came out again and was replaced with the SPC. 

I’m sure the RR oil is good and I understand it has friction modifiers as suggested above, but I’m not sure it’s a cure all. 

[ScottR400D]

Garth, speak to a race team, I think they have to use them........

......and think yourself lucky, I’ve got a newly rebuilt BMW/Titan full assembly sitting on the shelf! 

 

[CtrMint]

 

I usually jack the rear up each side on the outer A frame point, stick a bit of 9x2 timber under each tyre then jack up off the diff.

Are you refering to the 420 or 620 rear exit. 

Thanks

Mark

[Wrightpayne]

Its an S3 dedion k series. My ally jack wont go under the rear (to the diff) without putting it on blocks. I can get to the dedion lower bush but dont like jacking it from that point as has been suggested can cause dedion failures.

[7 wonders of the world]

Mark,

Drive the 620 onto a couple of pieces of 4x2 timber under the rear wheels, this should allow you to slide the jack under, lift it and remove one piece of timber and lower back onto the other.

 

[ChrisC]

Since my 1000 mile diff read exactly the same reading on the same brand torque wrench.  I was being to suspect the reason my diff is noisier than other sintered plate diffs I have heard (even with RRT Oil) is maybe my preload is on the high side.  I might try adding an extra dose of LSD additive, I have some in my spares collection, worst case I do another diff oil change.     

[ScottR400D]

That may be just curing a symptom, not the problem. 

 

[CtrMint]

Are you now saying high preload is bad?  I thought it was a cause for higher than average knock noise, which can be reduced with an additive. 

My understanding was the diff had the same mean team to failure regardless of the initial load, and the load was just a basic indicator of health, i.e. <20 = rebuild and potentially costly damage to additional component wear.

There's no suggestion at this time mine or Chris's diff will fail quicker for having a relatively high preload?

[ScottR400D]

No it presumably won’t fail any quicker than another Titan diff. 

The point is that other makes of diff, that have longer lives than the Titan, based on what we know, don’t start with anything like 50lb ft preload. That’s the sort of preload you’d only expect on a race car of that weight, if even then.  

I know I bang on about the SPC but it’s my only reference. It starts with about a 25lb ft preload which beds in to 20 or so then stays there. 

But the SPC works very well at that preload, where the Titan doesn’t seem to. It seems to need 40/50lb ft to work properly but as a consequence is very noisy. When it wears to where the preload falls to 20/30lb ft, the noise reduces but then the diff isn't working properly. 

As aerobod said earlier, you can add friction modifiers to reduce the chatter caused by the high preload but that also reduces the effectiveness of the diff locking. I’m sure you can get a good balance for a while but once the plates wear a bit, who knows. The point is, all that shouldn’t be necessary. 

So, as I said, changing oil to reduce noise may be just treating the symptom of noise caused by a high preload necessitated by some design issue which means the Titan has to start life with a high preload to enable it to function for more than a very short time. 

I stand to be corrected. 

[ChrisC]

Before the hares are set running again, its fair to say preload is part of diff setup/setting, choose by CC and Titan.   It appear my lat 2019 kit, with 1000 miles on the clock and Marks 2019 car with 3900 miles share the same preload setting.  My preload was first tested (with the same reading) post IVA, which was at 200 miles so as close to new OOTB as you can get. 

Basically what's now being questioned is CC's setup.

[ScottR400D]

You're right Chris. Why is it set so high for a light road vehicle? What happens if it's set lower? It would be interesting to find out? 
But it does appear that the noise is caused by the high preload, which CC, presumably, wouldn't choose unless it was necessary for some other reason. 

[ScottR400D]

You're right Chris. Why is it set so high for a light road vehicle? What happens if it's set lower? It would be interesting to find out? 
But it does appear that the noise is caused by the high preload, which CC, presumably, wouldn't choose unless it was necessary for some other reason. 

[aerobod - near CYYC]

Titan's spec on preload for Traction Master LSDs is 20 to 80 lbft depending on application:

[7 wonders of the world]

The Titan is a poor design:

Insufficient clutch diameter to transmit the torque or offer a reasonable lifespan without need for major overhaul.

The ramp blocks also move too much which permits deflection of the bellevilles beyond their designed working range leading to fatigue and fracture

The loss of preload due to clutch wear then reduces the preload to nigh on sod all, which results in a heavy knock or cluck which can be experienced on drive or overrun (power on power off) as the ramp blocks impact on the casing without the bellevilles offering any resistance.

You can replace the bellevilles, clutch plates and oil until your blue in the face but in essence your just trying to polish a turd.

 

 

[Grant_7]

Update from my end: my new Tracsport LSD is ready for collection. That's a turn-around of 8 days (6 working days).

When I dropped the diff off (video below of initial findings) one other area of concern was my pinion bearings. To rotate the pinion, it felt rough and graunchy. Steve Perks has removed the pinion and said that the bearings resembled lead, which he believes is due to the carbon in the oil (which should have been on my plates!).

So it's new Tracsport LSD, new pinion bearings and a magnetic sump plug for good measure.

Initial video: 

[ScottR400D]

#241 That’s as may be but Caterham and the guy who is rated as the leading authority on these in the UK, even by CC who recommend him to customers with issues and have their race car diffs built by him, recommend and set the LSD to 50lb ft for road use and recommend a rebuild when it’s down to 20lb ft. 

You seem committed to the Titan, James, and that’s up to you but I honestly doubt you’ll convince many over here that it’s any good. This and several other threads on here are too full of problems to ignore. 

 

[aerobod - near CYYC]

Peter, it seems that the low mileage failures are due to the more recent carbon plate design, as opposed to the older one that I have. I'm willing to try the Sintrak sintered plates in my diff. In terms of operation the TItan gives excellent locking and very predictable handling when functioning correctly, which it has done for over 30,000km in my car. The cost of changing to the Tracsport is about triple or quadruple the cost of doing the rebuild myself. I will see how the Tracsport diff wears over the years as more people such as yourself put it in the BMW diff. Maybe in another 5 years I will decide whether it is worth changing to the Tracsport or just do another Titan rebuild if needed.

So far there is evidence the Titan is problematic, but not enough statistical info to draw solid conclusions about how widespread the problem is over all cars, as there are tens of people here with issues, but I estimate that if 30% of the cars over the past 10 years have been fitted with the Titan LSD (since the change over to BMW diffs), there are about 1,500 cars with it fitted.

If I have to rebuild at 10,000 miles as recommended by Titan, I will probably do that, but any less I will look at swapping to Tracsport for my next diff maintenance in 5 years or so. With two new tracks opening in the Calgary area in the next 2 years of which I have a membership in one and time at the other and the track in Edmonton, I should be able to get 10 or 12 track days in per year, which will give the diff a good thrashing compared with my previous average of 3 days per year, hence probably triple my hard use rate to speed up my rebuild decision.

[ScottR400D]

I agree that it appears the issue has arisen since the carbon plates changed 5-6 years ago. Phil Stewart told me that. I also think it's much more of an issue with more powerful cars; I know several owners with 135/150bhp cars who don't appear to have the same issue, as might be expected, though none of them are Sintrac so I'm not sure what the NVH is on a lower powered car, they may even have a lower preload?

I agree that we are only in the tens in terms of known failures but it's early days; this issue has only been focussed on and the options known for a few months.

It would be interesting to see how many owners of 200bhp + cars made in the last 5-6 years, being made aware of this issue, have found their diffs had failed or are now questioning the answer TADT, that they were given when they complained about NVH in their Sintrac units. My feeling is that there are quite a number and I'm aware of few, if any, who would say their diffs are working nice and quietly. That's what Geoff is trying to establish with his survey.

I'll be interested to hear your view of the sintered plates. That seems to be an option in terms of longevity (possibly) but the associated NVH is unacceptable to me, and others it seems. I am now also aware of the effect the high preload has on the general feel and handling of the car in road use, so, again for me, it's not an option any more.

Anyway, think I'm going to pull my horns in now, it's all becoming a bit obsessive with me! I will certainly update my experience of the SPC LSD as I go along but for now I couldn't be happier with it. It's changed an unruly beast into a car that's a pleasure to drive fast and is near enough silent to boot and having experienced the Sintrac Titan in between I appreciate the benefit of that last point.

I'll comment if I think I can help anyone or answer any questions but enough of the theorising, I think!

[Geoff Brown]

'After initial break-in the preload may relax slightly'.  Yes it will & because of the internal design of the Titan, especially those with carbon plates. The preload will reduce to nothing rapidly. 

The failure of the Titan is not expressly due to the bhp output of the engine more to do with the torque that is received, multiplied & distributed by the diff which is a different subject all together.

Yes please more occurrences to collate.

[7 wonders of the world]

The LSD is subjected to the engine torque (not power) multiplied by the compound gear ratio (gear ratio x final drive ratio), naturally the highest torque figure will be obtained in 1st gear, (well technically in reverse) but you don't see many 7's doing intentional 0-60 sprints backwards   

 

[Geoff Brown]

Collected diff from SPC yesterday (22nd) now hanging in car but as usual life interrupts the process so maybe on Sunday I can finish the refit off    I now have a Titan LS unit as a paper weight or door stop!

For those that may be interested I did send a 'polite' non litigious letter to Graham Macdonald on the 10th October bringing his attention to the Titan problem. As if he or others at CC were not aware!

Either (1) it got lost in the post (2) got lost in the CC internal mail system (3) was received & the gears of industry are taking time for a considered reply (4) it was read, instantly dismissed & consigned to file 13.

So if you are out there CC reading these pages & you do. Whether it be Dartford or Crawley pull the digit out & answer honestly as this thread is not going away any time soon. 

 

[Wrightpayne]

Did you send it 'sign for'? I always send complaint type letters like this (not that I have much to complain about)

Ian