How to tell which diff on 1986 350I

[dukeenfield]

Hi,How can you tell which diff you have on 1986 350i,a non limited slip type diff or powerlock type limited slip diff,as they use different oils.

[sevans]

If it's a powerlock there should be a small metal tab with 'PL' stamped on it that's under one of the rear cover housing bolts. There should be another tab with the diff ratio. If that's no good then jack the rear end up and turn one of the wheels. If the other wheel rotates the same way then it's a power lock.

[19560]

sevans said:

If it's a powerlock there should be a small metal tab with 'PL' stamped on it that's under one of the rear cover housing bolts. There should be another tab with the diff ratio. If that's no good then jack the rear end up and turn one of the wheels. If the other wheel rotates the same way then it's a power lock.

Yep, seconded. J

[shpub]

I would do both checks as I have found those pesky little tags to be wrong.

When I took the old diff out of my car, it had no powerloc tag and was a 2.88! It was most definitely a powerloc and had a 3.54 ratio, measured by turning the input shaft. Who knows when/why/how they were changed as it was the original diff.

[leorest]

dukeenfield said:

Hi,How can you tell which diff you have on 1986 350i,a non limited slip type diff or powerlock type limited slip diff,as they use different oils.

Mine is an 85 series 2 350i and definately has LSD.
As far as I know the factory had standardised on LSD by this time (only an option before) so if it's the original one fitted to the car then yours will most likely be the same. Having said that it is TVR so best do the spinny wheel thing
L

[19560]

leorest said:

Mine is an 85 series 2 350i and definately has LSD. As far as I know the factory had standardised on LSD by this time (only an option before)

Sadly it was still an option then. J

[paul gotts]

sevans said:

If that's no good then jack the rear end up and turn one of the wheels. If the other wheel rotates the same way then it's a power lock.

But if it is an LSD do not force one wheel to turn whilst the other is static / on the ground. Damage to the internals may ensue.

I thought an LSD was "standard" on the 350i.Mine certainly had it, and was an '86.

[leorest]

paul gotts said:

I thought an LSD was "standard" on the 350i.Mine certainly had it, and was an '86.

19560 said:

Sadly it was still an option then. J

leorest said:

Mine is an 85 series 2 350i and definately has LSD. As far as I know the factory had standardised on LSD by this time

I love TVRs.
Though it's possible that Paul and mine could have been optioned up it is equally possible that TVRs changed with the windIsn't life exciting
L

[FrenchTVR]

Empty bit of road, 4000rpm, side step clutch. Once smoke has cleared see if you have one black line or a nice neat pair

[rev-erend]

Get that change of underwear ready if it gets out of shape too

[dukeenfield]

Thanks every one for your help,I will have to check,but got it all in bits at minute,trying to change rear springs and dampers.