BMW/Titan LSD Viability

[7 wonders of the world]

Billy I would opt for an open diff and send it to Steve @ SPC to pop a Tracsport in for you, easy if you are building the car...?

I certainly would not be buying a Titan..

[Billy.Whizz]

#276. Unfortunately I have paid my second deposit and cannot change anything now as it's a factory build, so when I get it I will run it for a year and then get the SPC Tracsport fitted.

[ScottR400D]

#275 I think the response to that is “Yeah, riiiiight.......” accompanied by a wink. 

Tell them to have a word with George Campbell. 

 

 

[7 wonders of the world]

Billy,

I would be talking to them now, this is an easy part to change assuming the build hasnt started, as both are stock lines for CC, deposit means nothing. I certainly wouldnt be accepting a Titan.

 

[ScottR400D]

I agree with 7W but if they don’t agree I wouldn’t be waiting a year. I’d have the diff out ASAP, have the SPC fitted and flog the Titan off to a race team. 

After a year it will already need rebuilding so won’t have much value. 

 

[Geoff Brown]

Billy the sales staff are 'bull shi**ing you. Of course they are aware but would they tell? Of course not. With no advice on the BMW/Titan diff servicing at point of sale or in the owners hand book of course there is nothing wrong.

As you are the customer argue your corner & insist on an open diff. They are off the shelf components ready for fit.  Only a small amendment to the build sheet unlike specifying lowered floors at this point. That decision will save you heartache when in the second year of road use the Titan could say 'hello'.

When I was at the second deposit point with my car I decided that the fitted RBTB route was best instead of returning for a retro fit. CC resisted but in the end agreed. My argument was my money, the upgrade is available so what is the problem as the RBTBs are just another component fit. And its a kit!

Again does any one out there know the CC e mail address for Macdonald?

[ScottR400D]

Going from the format of the few I know it could be

graham.macdonald@caterham.com 

He’s also in Twitter, if you are. I’m not but saw some posts from him. 

[Geoff Brown]

ScottR400D #282 - Thanks. I recently phoned CC & inquired about my letter & apparently the operative I talked to would follow up personally with GM. We will see, pinch of salt, pigs may fly etc!

[ScottR400D]

Someone answered the phone!!!???

 

[John Vine]

Re #281:

As you are the customer argue your corner & insist on an open diff.

I agree.  And I imagine there'll be a significant price adjustment in your favour, too.

JV

[Rob Walker]

I have followed this thread with interest and have the following comments.  All plate diffs will wear during normal cornering ie road use when both wheels have grip the diff will only lock when grip is lost to either wheel.  In terms of durability I have run with ZF plate diffs in all my sevens since 1997 and clocked up over 70,000 miles with lots of track time 10 years ago I have only twice needed to have my diff overhauled,  once the plates were turned over and re-used , the other the plates were replaced.  I think its fair to say that the ZF plate diff has proved itself as very durable, I also know several other owners who have run with the Quaiffe ATB units and once again these have been bombproof its only weakness being shock loading coming off curbs, easy to be sympathetic and avoid this.  My other observation is that I do not agree with others who have said that there is no difference between the Ford and the BMW casings, the Ford is cast Aluminium and the BMW is cast Iron, they both have quite different coefficients of expansion, its been my experience that when pushing hard on track with the Ford the case expands more than the Diff cartridge and this takes a lot of the side thrust off the bearings that locate it. result the diff becomes very noisy and transmission backlash increases.  The BMW should be more stable in this respect.  I am sorry that I have no experience of the Titan but would say that there are a lot of happy owners out there that have had not trouble with their diffs, it must be very worrying for owners to hear stories from a handful of owners of failed units but this needs to be put into context of actual numbers, and also keep an eye on the static preload, swopping to the more durable sintered plates when preload gets below 20 lbft.  I have been given advise on lubricants by well known Caterham transmission specialists but found Castrol Hypoy LS has worked better than anything in my diffs.  I consider some of the new GL5 too slippery.

[Geoff Brown]

Hi Rob,

Thanks for your input the more the merrier.

You mention that there are many happy users of the Titan but there are many out there that are keeping their heads below the parapet.

The sintered plates are a step in the right direction but the Titan recommended service interval still prevails. This essentially means the diff is revisited at least every 10000 miles taking track days into account which could mean dropping the diff annually. Personally most owners do not want that nause of endless repetition & unnecessary dismantling.

The other problem is that later LSDs also not uncommonly suffer from harsh NVH straight out of the box - 'clonking' as most put it. An indicator of poor diff set up which eventually will kill the Titan as well as other internals? Trouble is Caterham & dealers all say the same thing - TADTS.

 

[ScottR400D]

Rob, I’m not sure what you’re offering is either helpful or relevant, in all honesty. As you say, you have no experience of the Titan.  

It’s all been said and discussed and there’s little doubt that the Titan is just not fit for purpose in more powerful variants. If you really look at all the threads on this and speak to owners as I and others have done you’ll find that it’s a very small minority of owners of the more powerful cars who are happy with either the performance or longevity of the Titan.

Several of us have also had it demonstrated and explained to us just why and how the Titan isn’t fit for use in those cars. If you believe it’s just a ‘handful’ of failed units perhaps you can explain why those units failed? There’re lots of images of the wear and reports of the failures which appear to show clear and consistent design issues unless you know better?

Just because the ZF plate LSD worked doesn’t mean all plate LSDs will. We know the principle is sound, but if the principle isn't properly applied through design then you get the result we have seen. 

If the Titan was at all suitable for those cars CC and Titan wouldn’t have begun to fit the unbearably noisy sintered plates and wouldn’t have surreptitiously slipped in ‘maintenance’ recommendations that were never given to purchasers and still aren’t. Until they complain.  Nor are they included in the CC handbook to the best of my knowledge. 

Incidentally, if an owner sticks to the recommended maintenance programme, dropping the diff for a rebuild every year or 10k, should the LSD last that long, it’s likely that servicing the diff would cost more than all other servicing put together. Does that really sound right?

 

 

 

[DJ.]

I found Rob's post interesting

I completely understand several contributors to this thread have had extremely bad/expensive experiences with the Titan LSD, but I have done about 35000 miles with a sintered plate Titan and it has not been "unbearably noisy" and hasn't let me down. As Rob says it is likely that there are a silent majority of owners whose experience has been similar to mine. Thanks to this thread, I am now aware that the preload is too low on my Titan, and it requires a rebuild.

I really don't fancy taking the diff out every eighteen months at my annual mileage, so I have decided to replace rather than rebuild. I have bought a Quaiffe ATB.

As Rob said:

I also know several other owners who have run with the Quaiffe ATB units and once again these have been bombproof its only weakness being shock loading coming off curbs, easy to be sympathetic and avoid this.

With no maintenance, a price of £480 including vat and delivery from Burton Power, it seems a bargain. I accept I will lose drive when one wheel is actually off the ground, but the way I drive it isn't going to happen often and I really don't care about lap times.

Duncan

[StevehS3]

DJ, does your diff need to be returned to have the intervals changed or can you do that yourself? If so, is that relatively easy to do? 

[DJ.]

I have a friend with an MK Indy which has a Sierra diff, and he fitted an ATB last year. He fitted it himself and told me it is quite easy, and has offered to help me do it over the winter.

I am lucky, because when I fitted my Titan, I had it installed in an old Ford diff, and left my original hardly used diff safely sealed and stored away. I plan to put the ATB into this lower mileage diff, so the pinion bearings should be fine. My friend suggested I buy new driveshaft oil seals and also crown wheel bearings to make it easier. All the parts were approximately £540. I believe the most difficult part is adjusting the backlash properly.

If there is interest, I can take photos and post it here, but it won't be until after lockdown ends.

[7 wonders of the world]

I think you will find there have been a lot more failures than you or realise, the design of the Titan has been breaking Bellevilles form the day it was realised, Titan simply sold people new ones, they did look at the excessive plate wear however again the design is such that even the later type suffer premature wear.

The ZF is the yardstick against which others are measured, a proven design form back in the 60's....

The Quaiffe cannot be compared as it is and ATB not an LSD, and offers very limited benefit over an open set up.

It's fair to say a good few owners where sold an LSD when ordering a new car along with big brakes, not knowing th benefit of either, and quite probably dont drive the cars with sufficient vigour to actually need it.

Those who do, find the obvious short comings of the design pretty quickly, 

I have no actual data to support this but I would like to bet the percentage of ZF LSD's that have either failed or needed expensive rebuilds is insignificant compared to the amount ot Titans needing this service.

 

[ScottR400D]

#289. DJ, if your sintered plates Titan has been fine for 35k why not just but a rebuild kit for £250 and rebuild it?

It’s not compulsory to strip and rebuild every 10k, if you can get 35k and it’s not noisy why change?

 

 

[DJ.]

That's a good question

I've been giving this a lot of thought. I don't have the expertise to rebuild the Titan, so it would be rebuild labour plus the rebuild kit. £250 is going to be the absolute minimum, but I'd put money on it being more than £400  and probably near £500. Now I know about the preload torque, I can see a future where I keep nervously jacking up a wheel and breath  a sigh of relief that it is more than 20ftlb. Also ATBs are very reasonably priced currently and my friend (who has been impressed with his and is a better driver than me with race experience) will help me fit it.

In the end, I decided the ATB is going to suit my 95% road use well and I will be much happier knowing it isn't going to need regular rebuilds.

If I was a competitive track driver with more power, I would probably go for the Tracsport LSD as I accept kerb hopping is going to be really bad for an ATB equiped car.

[Geoff Brown]

DJ - I am very surprised that your Titan has lasted so long irrespective of having sintered plates as there are other weaknesses that cause problems early in it's life.

The failure of the springs for a start. When you open up your diff I would be amazed if there was not some shrapnel lying about &/or the springs are cracked, the thrust washers worn thin.

I presume that you have changed the oil regularly so the colour has not given alarm nor the presence of debris?

A wise move changing from the Titan - anything is better especially for a higher torque output engine.

[Geoff Brown]

The plot thickens - Not 100% sure but CC were supposedly still offering Titans with carbon plates at least until 2018 with a view to moving to sintered plates as standard.

Up to that date customers could specify sintered plates. Obviously this was only if they were aware of the weakness of carbon plates. 
Apparently race car Titans are fitted with with sintered plates. 

 

[DJ.]

I'm sure you are right Geoff. I think I have been lucky, and it was only a matter of time before it failed and damaged the crown wheel.

 

When I had the diff fitted (not by Caterham) I was not made aware of any advised service interval.

 

Thank you for starting this thread

 

Duncan

[David_Long]

As promised earlier in this thread, I stripped down my Titan diff. I will do a full report on my blog but i thought it worth a post with the headlines.

This diff was purchased in a Sierra housing in early 2013. IIRC it was pre ordered about a year prior but took sometime before it was in production and delivered.  So this is an early example. The car was essentially an R500 spec car with various stages of tune between 260 and 300 bhp. It completed over 60 sprint events and probably 3000+ miles, some of which was trackdays, before being swapped out for a different final drive ratio in 2018. It was still in occasional use when it's ratio was required. It had regular oil changes with Redline Heavy. Prior to being stripped down it was tested on the bench for preload and gave around 25-28 lb ft

The first surprise was that it was sintered plate and not carbon. The second surprise was it all looked brand new. No significant wear anywhere. Springs were intact with no obvious damage. 

Witness marks show the Belleville springs were flattening (100% defection) microscopic witness marks on the first plate (the spring side) suggests debris in the oil was imprinting into them. This could be a clue as to why the springs fail i.e. dirty oil may generate stress points and cracking. - perhaps a 100% defection was a poor design decision in respect to longer oil change intervals. 

Later in the winter break I will look at the second diff and report back. It's done only two years (12 sprints) and may be a carbon plate one.

[Geoff Brown]

Thanks David - Good to know that someone has been 'lucky'. But it seems that the Ford diff is not notorious for failures as is the BWW/Titan combo. With that in mind there must be an inherent design & application problem when fitting the Titan to a BMW diff?

Unusual to find sintered plates as the understanding is that carbon plates were fitted as standard up until at least 2018 unless specced otherwise.

The only problem that your Titan has in common with all Titan applications is the 100% deflection of the springs as revealed by the witness marks shown in your pic.

At least in an SPC LS unit the springs are restrained from 100% deflection by good design.

 

 

[David_Long]

I'm not sure 'lucky' is the correct term.

The factors that prolong it's life are:

• Used in the way it's design was intended to be used - flat out on the track.
• Oil changed regularly
• Good quality high viscosity oil