Searching for a hard to find part

[CGoldone]

I’m looking for a LSD 3.54 ratio for a 2002 tii.  I know this may provide a laugh or two with how hard these are to find, but more surprising things have happened...!   I’d love to get any leads or even if you have one that’s available.   Appreciate it.  

[Son of Marty]

Do you mean 3.45? you can put just about any gearset into a lsd housing in this case it maybe easier to source the parts seperatly 

[CGoldone]

44 minutes ago, Son of Marty said:

Do you mean 3.45? you can put just about any gearset into a lsd housing in this case it maybe easier to source the parts seperatly 

Hi Son of Marty, is there somehow a contact for you.  I’m not familiar with this website, but I could not find any private message type of contact.   Thanks

[roadhog0]

29 minutes ago, Chris Smith said:

Hi Son of Marty, is there somehow a contact for you.  I’m not familiar with this website, but I could not find any private message type of contact.   Thanks

He didn't give any source for parts? What he's saying is it would be easier to find a 3.45 gear set then put an LSD in it. Basically take two diffs and make one. I can't help with the gear set, I've got 4.10's running around....

[Mike Self]

Chris, it's gonna be very difficult to find a 3.45 diff, open or limited slip, in the US, as our tii's all came with 3.64s, and virtually no US spec 2002s at all came with limited slip diffs as they weren't part of the Federally approved drivetrain package.  

 

There were rumors that very early US-bound 72 tii's came with 3.45 diffs, but so far no one has found one.  And apparently the only way you'd get a limited slip here was either to be a "friend of Max Hoffman", buy an LSD as a spare part from BMW (or Alpina) and install it yourself, or take overseas delivery straight from the factory (military, diplomatic corps, etc) and not ordered through Hoffman Motors.  

 

You might find a 3.64 LSD from an early E21 320is (77-79, with a 2 liter engine) but they were rare to begin with, and are even rarer now.  IIRC Euro E21 323's used a 3.45 diff, but again, they were never imported.  

 

Sorry to be Debbie Downer, but you've got a tough row to hoe there!

 

mike

[PaulTWinterton]

 

11 hours ago, Mike Self said:

Sorry to be Debbie Downer, but you've got a tough row to hoe there!

 

Well...on the advice of @Preyupy,  last year I sought out a 3.45 LSD, as it adheres to the stock delivery option of tiis in Europe.  I like my car to remain as close to stock as possible so this was a valid purchase IMO.

 

I found this vendor in the US:
 

https://www.ebay.com/itm/BMW-CUSTOM-3-45-LSD-POSI-LIMITED-SLIP-DIFFERENTIAL-2002-TII-320I-25-40-lock/233672596096?hash=item3667f8da80:g:Kw8AAOSwnh5cTm34

 

Pricey, but it was plug n play, and the vendor was great to deal with.  I've been enjoying it immensely ever since.  It also corrected my speedo/odometer.  With the CN36 Pirellis and the 3.45 my speedometer is exactly the same as my GPS speed reading.  Couldn't be happier.

Edited October 5, 2020 by PaulTWinterton

[jgerock]

10 hours ago, Chris Smith said:

I’m looking for a LSD 3.54 ratio for a 2002 tii.  I know this may provide a laugh or two with how hard these are to find, but more surprising things have happened...!   I’d love to get any leads or even if you have one that’s available.   Appreciate it.  

Before you buy one, tell us about your car (how it is set up and your style of driving).

 

 

[CGoldone]

Thanks to everyone for their comments and referrals.  I'm going to contact both suppliers, although it says that for the ebay seller that he does not accept messages due to the high volume.  And there are no returns...  Not sure if I want to buy something blind, altho maybe this is pretty straightforward - "it is what it is"...?

[kbmb02]

@Chris Smith

If those other suppliers don’t work out, send me a PM (I should have what’s required to build a 3.45 LSD). -KB

[CGoldone]

In response to jgerock:  Original condition (except for heavier sway bar, electronic ignition), relatively low mileage, just installed original-style Michelin XAS tires (had original second set of tires), has an as-new feeling four speed transmission.  To be used for average short mileage local driving, but I don't like the higher revving at higher speeds.  I prefer not to put in the five speed gearbox.  

[Son of Marty]

2 hours ago, Chris Smith said:

To be used for average short mileage local driving

Then why do you need it to be a LSD?

[irdave]

13 hours ago, Son of Marty said:

Then why do you need it to be a LSD?

 

Hooning.

[TobyB]

I have a 3.54 limited slip in my tow rig- I'm sure the Ford Corporate 10.5 would weld right into a 2002.

 

As to 3.45 diffs, they're not too hard to make out of a 318ti limited slip and a later 6- bolt E21 case.

 

t

[chargin]

I put a 3.64 into my freshly built Tii, 2 weeks later I pulled it out and put the 3.91 back in, a 3.45 would put right in line with a Smart car for acceleration, on the bright side you should still be faster 45-70 than a VW bus...... 

[CGoldone]

Hey, thanks again for all the opinions - one end of the spectrum to the other.  “Love it”, thru to “took it out”...  Also the recommendations led me to two sources for the ratio if not an original box.  

chargin:  I like your description,  but do you know the actual specs (say 0-60 mph or some other common measurement) for a otherwise standard tii with the 3.91 and the 3.45 respectively?   I don’t know of a formula that you can apply to calculate one if you know the other, but there must be a source for that information.  If one truly goes from a rabbit to a turtle, then that’s something to think about.  
Thanks again for all the responses!