I haven't problems with my overdrive not disengaging and I've been doing some research and looking at exploded views of the parts inside. It looks like there's a gasket, filter, and magnet to clean. I see the filter at IPD. I also see an overdrive rebuild kit. but from the exploded views I've seen I see another filter above the plugs that require the special tool. I don't see that in the picture of the OD rebuild kit?

I figured I'd plug out that 2nd filter and hopefully replace and pressure relief valve and clean it, and put all the appropriate new o rings back in there place.


88 740, manual

 

which gearbox? is this m46 with the P or J-P type overdrive? as I read my parts lists, the 88 740 non-turbo came with the M47 5-speed transmission, while the 740T came with the m46 4 speed plus separate overdrive.

re: whats in those IPD kits, you probably should ask IPD worse, my diagrams indicate there's 12 different OD units and it would take way too long to figure out what parts are in which. the type P and type J-P look somewhat different.

 

I swore "mitchel ondemand" said the turbo was the M47. I have a 740T.

right I should just call IPD. I was looking for some insight from anyone that's possibly rebuilt one of these units,

 

Definitely an M46 behind a turbo motor...for what it is worth, when these cars were new the dealership would rebuild the transmissions in a heartbeat but when it came to repairing the D, J or P Laycock OD units they merely swapped 'em out. There's a lot of stuff in there to put back together incorrectly. I'm talking back when techs needed to be a bit intuitive rather than read a scanner. Two things the dealer would not go into? The OD unit and the K Jet fuel distributor.

 

ok, then it's a m46, I'll remember that from now on. Fortunately for me I have a few OD units at my shop I can play around with before I get to crazy with mine.

That's the automotive industry now. Alternator, starters, brakes, etc. don't get rebuild anymore. cheap labor and cheap parts makes it more cost effecent to just replace everything.

 

[QUOTE=guest01;269379
That's the automotive industry now. Alternator, starters, brakes, etc. don't get rebuild anymore. cheap labor and cheap parts makes it more cost effecent to just replace everything.[/QUOTE]

Well, it was the automotive industry then too. I'm talking about when the cars were new, 20+ years ago. While the Volvo green books are exhaustive in their information on rebuilding everything, the simple fact was, and is, that the OD unit and the old K Jet fuel distributor were highly complex with extremely small parts and very close tolerances. The techs back then knew what was wrong with the units; the issue was reassembly outside of a factory clean room with the proper tools was and is, nearly impossible. Tear into a dead Laycock unit and you will see what I mean. I've disassembled one...did not care to reassemble. My brother-in-law was a master Volvo tech in the 70's and 80's. He and his partner could dive into both front doors of a 240 with every tool they needed...and swap out a blower motor in 30 minutes. Being that good was how you made money doing warranty work that didn't (and doesn't) pay much. We have a 74 145 in the shop right now. The owner let the car sit for 10 years and tried to get it running. Got rust into the fuel distributor...as we had nothing to lose, we opened it up. Suffice it to say, we bought another...

 

our old british car mechanic rebuilt OD's (afaik, they were the same units in a 70s TR6 as in these 80s/90s 740s)... was an arduous and slow job, IIRC, it required some trial and error shimming to get just right.

on my parts diagrams, the only rebuild parts they show are a spring kit with 4 springs, a bearing (final output bearing? not sure), and for the P-type OD, they show a 'repair kit - reducing valve' which is a big stack of stuff with o-rings, sleeves, seals, and springs that goes in from the bottom... per tascaparts, this reducing valve rebuild kit, 271454, is still available(!) for $126. you mentioned two filters, the type P has a cylinder-like filter pn 380729 and a rectangular filter, 1220774, tasca has both of these too.

here's the parts diagram of the P type...

(click for full size...)

I'm with the swift one.... these are scrounge-n-swap, not rebuildable by anyone sane.

the note on part #22, for intsance, reads...ouch. 0.05mm is as thin as very fine human hair (50 microns...)