Tranny lifespan on '89 245

The manual tranny on my '89 245 just died with little warning, eg
from a slight noise to undrivable within about two weeks. The car has
169xxx miles on it.

1) This strikes me as somewhat soon for a failure of the gearbox. What
say ye?

2) Is there anything in particular that leads to this sort of failure?

3) I was suprised by the cost (~$2k for the factory remanufactured
tranny alone). Anything to say?


Input from James Sweet, Mike F, Mike T or Mike C very much
appreciated.

 

That is very unusual, in my experience the standard trannys have been nearly
bulletproof, in fact we've done numerous automatic to manual conversions for
that reason.

what exactly happend and what does the trans do now?

Vic

Ithaca, NY

 

Very strange,they normally last the car´s entire life.

 

It's been making a rattling noise in 2nd, 3rd and 5th for about two
weeks. Almost like a loose heatshield, except it's in sync with the
engine RPM. On the drive, when coasting in 5th it would occasionally
make a noise somewhat like going over rippled pavement.
Pulling off the interstate, I had to fight to get it out of 5th, could
not get it in 1st or 2nd at all (engine on/off, idling). Starting it
the next day to drive a block to the mechanic there was a horrible
noise coming from under the car (previous noises from the front of the
car) and very hard to drive. Diagnosis was dead gearbox/tranny.

 

While I am not an expert, I recall from one of the Volvo websites (Swedish
Brick, I think) that the M47 (5 speed) transmission was not known to be as
durable as the M46 (4 speed plus OD). Its shorter life was due to
insufficient lubrication because the oil filler hole was supposedly located
too low on the housing causing the oil level, in turn, to be the same.
Having said that the M46 is more durable, mine went out (1st and 2nd gear
synchos) at less than 100K miles. However, using the car in Seoul and Tokyo
might have contributed to this since the car was rarely shifted up to third
gear because of heavy city traffic.

You might consider replacing your defective box with an M46. They are
common in wrecking yards and not that expensive. Of course, you might have
to change the drive shaft too as the length of the two trannies will
probably vary. The M47 likely shorter without the added OD of the M46.

As I found out, most of this work is just parts swapping and, in time, a
suitable substitution can be done for a lot less than $2K. In my case, I
swapped out a newer M46 in a 745 with one from an older 240.

 

the m46 actualy uses a different flywheel than the m47, other than that its
just the wiring for the OD solenoid. Drive shafts are all the same in the
240 series.

Vic Ithaca, NY

 

Is that the 5 speed M47? They're known to be a bit weak and from what I
gather the fill hole is too low on the side so they're regularly run with
too little fluid.

I'm not sure why you'd even look at factory remanufactured manual gearboxes
personally, I've never paid more than $75 for a transmission and have yet to
have a dud, if there's a U-pull yard around I would encourage you to look
for a replacement, ideally an M46 4 speed with OD, you'll need the front
half of the driveshaft, the shifter assembly, and the wiring harness and
relay for the overdrive if you go that route. If you can find another M47
that would be easier.

 

Same flywheel, it depends on the year of the car, older ones had the flat
flywheel, newer ones (and turbos) had the dished flywheel. Clutch is
specific to the flywheel type, transmissions are interchangeable and can be
used with either the flat or dished flywheels. I put an M47 (too lazy to put
in the OD wiring at the time and thought it'd be cool and unusual) in an '86
245 using the flat flywheel from an '83 and the corresponding clutch. Works
fine, but if I were to do it again I'd go with the M46, I don't like the way
the 47 shift pattern is, after driving my M46 all the time whenever I drive
the M47 I tend to run the shifter into the gate between 3rd and 5th when
trying to go into 3rd.