South Wales Volvos

[rogerthechorister]

Model: Various!
Year:
Engine:
Auto/Manual:
Mileage (approx):

I'm trying to find out more about the P/J type overdrive fitted to some (at least mine) 16Vs - how does it relate to the J series and the P series? All info gratefully received. P was standard on post 88(ish) 7 series turbos, tougher than J and did not fit the same output shaft as the J.

Also trying to find out what model diff I want and where to get it to obtain a 3.54 LSD - my 16V has the 3.54 and it is so much nicer on the motorway than my 765T and my B280E both of which are auto and have the 3.73 rear end - but I want an LSD.

[Colin]

Some links for you...

http://wwwrsphysse.anu.edu.au/~amh110/Diff_LSD/diff_lsd_volvo_dana.htm

http://www.performanceforums.com/forums/archive/index.php/t-67185811.html

http://www.turbobricks.com/mods.php?content=art0014

[rogerthechorister]

Thank you for the info. None of those links mention the 1041 which a little more rummaging indicates probably to have been on later model 960s (solid axle ie estates) using the Holborn-Eaton mechanism and to become non-locking above 25 mph. Whether that is a boon or a bane is another question.

It's starting to look as if the only way to tell the rear axle ration seems to be to find the little plate on the back axle (I have never yet found one where the manual says it to be) or to jack u the back end twiddle the wheels and count.

My 765T with the 22 series autobox (so fourth should be 0.73:1) does speedo 80 at 3,100 rpm ie near as dammit 26mph/1000 rpm so that seems likely to be the 3.73 diff.

Must take the others out and check!

[Colin]

Beware the auto-locking diffs. Both my 960s (IRS) have/had the "Eaton Locker", and it's locked up at stupid times, like when pulling out of a junction. Result = front wants to go round the corner, rear wants to go straight on.

The plate you want will be buried under a load of crap....

[rogerthechorister]

So in your view despite the fact that they are weaker I want a 1031 of the right ratio, not a 1041?

Back to ratios. I just tested my 745GLT 16V, and at 2,000 rmp in O/D on the P/J (which could of course be a differnet reduction from the P or the J) I am doing 62.5 mph (speedo) ie 31.25 mph/1000rpm, which is off the wall. It would imply both a 0.69 reduction (which is only on the AW71 box, which I haven't got) and a 3.31 rear end which I shouldn't have.

Funny think is I met a bloke yesterday who reckoned that his B230 (non-turbo) was also doing only a whisker over 2000 rpm at 70.

So on this basis, unless I already have any (when I find the plates!!) I want 3 or 4 1031s with the 3.31 ratio. Hmm.

I did a spreadsheet calculating the mph/000rpm and attach it.

[Colin]

I think my dad's 940 LPT is little over 2000 rpm at 70...