yoramw

I have an 86 944 T with stock turbo transmission with the oil cooler and without LSD.

As I am getting more and more into track days and even small racing events, I feel the need to add an LSD.

I saw there are many options starting from Quaife & Wavetrac torsen LSD to Guards & OS Giken high end clutch based LSD, to a rebuilt factory LSD...
Budget constraints steer me away from a new Guards or OS Giken LSD.
I understand that for trail braking, clutch based LSD is recommended.
Is a rebuilt factory LSD be a decent option (it is much cheaper than the two former options)?

Is it true that I will have to give up on my oil cooler if I switch to a rebuilt LSD unit?

If anyone has recommendations on which LSD to get or where I can find a good price on either good used or new unit, please send it my way...

Thanks

Humboldtgrin

951and944S

If you go with a period correct 944 factory clutch type, the m414 pump was offered with both with/without lsd so if you source either a used one and rebuild it yourself or a freshened one, you should be able to swap over the m414 pump/cooler option.

If not, it's not the end of the world, there are other cooling options.

I can give you an idea on parts only for the refresh and the swap if you find a used one and want to do it yourself because I am currently freshening one of our race cars right now and ordering parts this weekend.
Keep in mind, you will have to split the gear cluster from the main housing to remove the diff so there are some gaskets required that are also in this list.
You will definitely need R & L carrier bearings, since, while possible to transfer them to the new diff, I don't know why you would want to at $30-$40 each averaged.

Personally, this is a lot of work and trouble to just not go ahead now and totally disassemble and replace necessary bearings and do all the synchros but that is a choice you will have to weigh.

On the parts front, all I have to offer is a slightly used Quaiffe but I disassembled it completely to clean and check since the transmission it was raced in for just 2 outings since new lost pinion teeth and I wanted to make sure that if I sold it, it was still in good shape. I haven't had time or need to reassemble it because we race the clutch types and one of our cars is 968.

I have ring gear bolts on this list because I consider them 1 time use for a race car, your mileage may vary.
Also, I rarely reuse the drain and fill plugs, @ $4-5 each, they aren't worth my time cleaning.
Your external splined steel plates are more than likely going to be 2.0mm, I use the 2.1mm (there is also a 1.9), so you will really want to disassemble any used unit and make measurements of the plates and follow the manual on other measurements.
The cup spring is what applies the loaded pressure on the plates against the thrust ring, so I change it as habit.
The "nuts" are really an insert that goes into the drive gear that drives your output flange and serves as the thread that your axle flange center bolt attaches with.

951and944S

BTW, I already know pricing on these parts close enough to guesstimate each part price but you aren't close enough yet to require that info.

You can easily copy and paste in google anyway.

I have one spare factory clutch type but not willing to part with it, but Rennlister "Dimi" here on the forum might have one either ready to go or in rebuildable condition for you.

T

Humboldtgrin

951and944S

I don't know what you are asking.
My list is for removing an lsd from a transmission without a cooler, freshening to factory spec and reinstalling.
I stated that it was my own personal list for a car of my own.

If you meant the metal clad seal for the rear case cover that houses 5th gear and offers access to the split race rear bearing, you are correct, he would need one of he's not careful removing and follows the factory manual to spear it with a screwdriver...., but this was something I already have when I compiled that list.

[edit] = @ Humboldtgrin, I see now, OP already has all components for cooler.

T

yoramw

Thanks!
Very useful information mate!

Humboldtgrin

FHMotorsport

Based on my experience the most cost efficient approach would be a factory rebuilt LSD unit. In order to use it in your transaxle and retain the oil cooling system you will need the NLA from Porsche oil pump drive gear for the LSD.
However, I carry that part in stock in NEW condition.

I also carry good rebuildable factory LSD units that I can rebuild.

Thanks for the referral.

BTW, Your list of parts is spot on and I use it when servicing customer's transaxles.

gpr8er

Just my experience and keep in mind that's all it is.

I had a Quaife diff installed by Greg Brown at Precision Motor Works at the same time he went through the entire trans replacing all the syncros, bearings and seals also 2nd and 3rd gear. The thing was bitchin when it was done.

Well after about 2 years the Quaife came apart at the track sawing a giant hole in the case of my trans completely destroying the trans and money I had put into it.

Okay now what?



So I pop the Quaife out of the trans send it back to them and immediately get into a huge fight about warranty on this thing. Ends up they won't honor their lifetime warranty and I have to pay for the repair. The worst part of it is they send it back, the diff supposedly repaired and they assembled it wrong!

Needless to say I won't ever be buying a Quaife again.

Lucky Lart bailed me out with a factory LSD trans.

IMO the best option is the AOR. If not any of the other Factory LSD trans will work and a Guard diff is definitely a step up


edit..sorry for the bold type, was doing it off my phone

NCLA951

951and944S

You are thinking pinion bearings.

The left and right carrier bearings are cheap.

$50 will buy you both in skf.

https://www.pelicanparts.com/More_In...-517-185-C-M92
https://www.pelicanparts.com/More_In...16-409-123-INT

T

951and944S

Exactly, the drive gear for pump is pinned and has two bolts.

I would work a solution myself before tossing a good 944T trans that just needs an lsd vs buying a $1500-$2000 second hand S2 box with lsd.
That's not to even mention ditching the entire factory pump drive for a CV or electric driven pump and cooler.
That loop is always in the way anyway....

T

951and944S

No problem, as per PMs, I'm really more into automatics.
More money...
I do a fair amount of 944/968s but only ones that I meet face to face on site at the track.
They deliver it (no shipping) and they pick up at whatever track the schedule has that coincides when it is ready.
I already work a day day job, so sideline autos, manual race jobs and keeping up with our own fleet of 3 race cars is as much as I want to do.

I had Max Energy contact you (he said he did) for a front pinion bearing......, just to let you know he found it for $330 at the second source I recommended to him.

T

rlm328

Call Lart