BMW/Titan LSD Viability

[Guy Lowe]

[Benton]

According to the configurator just now  360 & 420 R pack still has limited slip diff ???

[ChrisC]

It seem to have been dropped as an option on the S models (from the website), but that's only a starting point anyway. After all if you want it, you can have it, hence you see non 620 with carbon interior panels, or non cup 420 with the Sadev. 

[Andrew 21 Edney]

Still listed as part of the 170 R pack, but no longer an option for the 170 S. Not sure why, but I thought the 170 used a Suzuki diff so the LSD would not be a Titan...

620 stil listed as having LSD in both S and R packs.

[GulfSeven]

Was always standard on R packs...

[Colin Heseltine]

Just done another pre-load check on my Titan diff in my 17 month old 420R.  The car has now done over 8600 miles and will do another 2200 in the next 5 to 6 weeks.  Car has done one afternoon track day at Donington the rest has been road mileage

Both wheels turn in the same direction and pre-load was 46ft lbs using a Clarke digital torque adaptor, this was checked 4 or 5 times.  Next used a good quality 3/8 drive wrench where I could bring up the torque on a pound by pound basis.  This was locked at 44 ft. lbs but moved when set to 45 ft. lbs.  Again this was done several times.

So far so good, fingers crossed.  I will check it as soon as get back from trip.

Colin

[Geoff Brown]

Colin H - #556 - Sintered plates so their life will not be leached away as quickly as the carbon plates............mmmm.

You may very well see a reasonably long life of the Titan. Serviceability checks on a planned basis as you are doing is the only way forward in monitoring the condition of the LS unit.

Would not be a bad idea to also check the condition of the oil after the trip & change it as a precaution.

[GulfSeven]

I've started checking pre-load as part of pre-hibernation checks each year. After 2 years (and one track day) it was 44 lb.ft so we'll see what it is at this year (after another 3 track days) in a few months...

[ScottR400D]

Whilst the preload checks will give you an idea about the state of the sintered plates they won't warn you of cracked or failing bellvilles. Though that is related to the rate of wear of the plates, of course.

An regular oil change with close look at the old oil, as GB suggests sounds a good idea and I'd be having a full inspection every 10k miles or so on a 420 or anything with more than 200bhp. 

[Colin Heseltine]

Geoff,

I was planning to get the oil changed. The car will be due its 12000 mile service before the end of the year at which point I will still have 3 months left on the two year warranty.  I asked Oakmere about the Caterham recommendation re oil changes.  I know someone one here showed the Titan recommendations, but I'm sure someone posted the Caterham recommendation but I cannot find it.  If someone can indicate which post has their recommendation I will chase it up with Oakmere.

I have got the magnetic sump plug fitted.

There appear to be several schools of thought re the oil, Motul 75W/140 or the GLS 90.  I assume the car has the Motul in it at present. Is it going to pay to continue with the same oil.

I changed from my 24 year old 1600K to get away from having to do jobs on the car.  At 73 next time round my back, knees and shoulders are getting past wraunching heavy bits from underneath cars.

Colin

[Geoff Brown]

Colin #560 - Unless I am mistaken CC do not recommend any oil change for the diff. TITAN recommend the service intervals for the LS unit but not any oil changes as the service cycle to drop the diff & overhaul the unit involves oil removal.

Whomever you entrust with the service may state that the diff oil change it is not required. I would insist that it be done on a precautionary basis especially as the car is nearly two years old. Request a report on the condition of the old oil & mag plug. If they know what to do also request a diff pre load torque break out check. BMW Differential Titan limited slip unit - how to check & protect while in service. | Caterham and Lotus Seven Club (caterhamlotus7.club)

One very easy health check of the LSD is to jack the back end up & rotate one wheel. If both wheels turn in the same direction you still have a relatively serviceable diff but the pre load torque break out check is the way to get the full picture.

As to the type of oil to employ I would stick with what is already installed as removing the oil by various methods will inevitably leave a residual amount so cross mixing could occur which is what one does not really want unless a flush with the new type oil is carried out which does create waste.

 

 

 

[ScottR400D]

I don't think the oil type is critical as long as it's the right spec and a reputable brand. CC don't appear to either, in the past 7/8 years they've had 3 different 'preferred' suppliers. 

Neither do I think a little cross mixing would be an issue, I had this discussion with Opie and they confirmed that as long as spec is maintained it wouldn't make any difference. 

The fitting of a mag plug is a no brainer. It's a good indicator.  

In the midst of my diff issues, I was quoted the Titan service requirements by CC. I take that as being CC's advice too and so they and their agents should require it during routine maintenance, IMO.  

That's not to say they wouldn't charge for it but there seems little guidance when buying a car, perhaps because a £1-2k bill every 2 years or so might put some people off? 
 

 

[Geoff Brown]

ScottR400D - I agree with your statement about oil type. Regardless of manufacturer/supplier as long as the oil is like for like - viscosity, synthetic, semi synthetic or mineral then there is not a problem.

If a decision was made to replace the oil with one of a different viscosity index, type (semi synth/mineral) then there should be some effort to remove as much residual as possible to avoid intermixing.

In aviation having seen what intemixing of oils can do to gearboxes & the like it is best avoided ! 

[ScottR400D]

I'd agree with all that but wouldn't worry too much about the VI. I've seen all sorts of grades from 75/80 to be 75/150 recommended. I've used both ends of that spectrum and seen no difference in performance so going from one end to the other, after removing as much of the old as possible is going to leave a fill that pretty near what it's meant to be. 

Of course, removing as much as possible is a given but I've found the Pela extractor quite efficient at emptying the BMW diff, leaving very little behind. 

[Geoff Brown]

I am dumping my diff oil next month. Replacing with same Castrol B373 SAE 90.  Its very viscous, stinks to high heaven & 'old fashioned' mineral oil but it works for me !

[GulfSeven]

So following on from last year's results (mileage 2,400 and 1 track day: 42 lb.ft preload), I've just repeated the checks:

Mileage 4,500 and a further 3 track days: 42 lb.ft preload again 

So far then, road and track driving in my car doesn't seem to be causing an issue. it'll be serviced in March (along with it's first MOT) after winter lay-up, so I think I'll get the diff oil changed then too as a precaution.

[ScottR400D]

Deleted original post. I've realised that we'll all have different experiences and believe what we want to. That's fair enough, have fun out there. 
 

 

[ChrisC]

It doesn't matter what positive information is posted on this thread/forum about the synter plated Titan diffs, it will be shoot down by the mistakes from the past and the price owners have paid for the lack of information at the time.  

[GulfSeven]

It's your guide I've been using to check the preload Chris, so thank you for writing it 

[Geoff Brown]

Changed Diff oil today as I thought that two year intervals were about right. So one year & eleven months & 3,518 miles later just a small amount of finings on the mag plug & the oil was quite dark. Grey but not black.

Fresh Castrol B373 back in for another two years.

I drove the car for twenty miles to warm the oil up so I thought that I would change the gear box oil as well as it has been in since build nearly ten years ago.

The drain plug well was full of finings & there were a few very, very minute feathery metal shards on the magnet nose. The colour indicated they were more than likely steel. The oil which is 80w90 mineral was NATO dark green in colour. Usually a light yellow with a green tint when new. So same oil back in for another ten years.

 

 

[Colin Heseltine]

Just done over 2000 miles spirited driving in last 2 weeks round Scotland. Preload down to 43.5ft lbs from 44ft lbs (manual torque wrench).  Electronic torque wrench shows  around 1ft.lb drop.  Car now up to 10700 miles in 18 months from new.  At the moment radiator is bigger issue than the diff.

Colin

[Geoff Brown]

Good to read your diff in fine fettle. But beware the pre load can fall off a cliff. Trouble is it is not if but when so preventative maintenance is the way forward.

Not another radiator !!

 

[Geoff Brown]

And the story continues - Just received an email from a non member George.

His 2016 420R LSD failed at 1640 miles due to failure of the carbon plates. I was not given the date of failure so cannot comment on what date the failure occurred, that it is a very under used car or the fact that George has only just found my club e address.

He received no sympathy or goodwill from CC which on evidence he would not. I pointed out to him that CC are aware of the problem but deny any responsibility at all especially for claims outside of warranty.

Typical !!

ARE YOU READING THIS BOB LAISHLEY AS YOU SHOULD BE ASHAMED

 

[ScottR400D]

1640? That's a record I think. They usually make 3 or 4k at least! 

A bit unfair to blame Laishley though. He's only been there 5 minutes, he might be in the verge of ushering in a new era of customer support...........

 

 

[StevehS3]

This is making me think I did well to get 4,200 miles out of mine!
CC should have taken responsibility for the problem and done something to help us out such as a discounted replacement diff. I bit of goodwill never hurts.