I'm a newb here. I have poked around on other sites and always find that you guys seem to have the best advise. Thanks in advance.

So I recently acquired a 93 245 with M47 and have been going through all the long neglected maintenance points. Noticed that the flex plate and center bearing were in need of replacement. Ordered all the parts including a rear most u joint and proceeded. After removing the shaft from the car I carefully marked the two halves at the slip joint. I then tried to separate the two halves and found that they would not budge. The only way to get the two apart involved fire and a BFH. I finally got it free and found that the splines were coated in some otherworldly resin that resisted all solvents, wire wheel, and fire. The only way I could get the splines cleaned up enough to reinstall was to heat it till nearly glowing and then scour it with a wire brush. The grease boot had long since vanished and i guess the grease just petrified inside the joint. Once cleaned up and greased it slipped nicely into place. All other parts went in without issue (u joint, center bearing and rubber mount, grease boot and flex plate). Reinstalled shaft making sure that two halves went back together the same way they came apart and took her for a test drive expecting to notice a reduction in the driveline noise. No such luck! Now I have a terrible vibration at and around 30mph and a low pitched drone. Vibration seems to dissapear on the highway.

My questions: is it possible that I warped the yoke on the slip joint when wailing on it? Could I have damaged the u joint (I only replaced the rear most joint, the center joint may be compromised now)? On a manual transmission,where there is no front u joint, the only relationship that must be maintained is between the two halves at the slip correct? I've heard that the 93s had a keyed shaft is this true? because I don't recall seeing a key. If I did warp the yoke then I will likely need a whole new shaft correct? or can it be straightened and balanced by a good DS shop?

I have managed to soften the vibration a bit by installing a hose clamp on the front shaft near the center bearing. This was a trial and error thing, install clamp, take for a ride, jack back up and tweak. But it is still not great and I want to resolve this so as not to put unnecessary stress on other components.

 

check this post out as it relates to your trans flex plate:
240 drive shaft flex disc install - Turbobricks Forums

I would just replace the following on the trans and drive shaft
Definitely the trans mount as I felt a huge improvement on my M45 no od. Unless yours is fine.

1) clutch fork spring $ 2 dollars if it is not hydraulic?
2) Trans mount $ 12 dollars
Driveline Rubber Damper Flex Ujoint...THERE IS A BOLT PATTERN OR SEQUENCE YOU RE-INSTALL THE FLEX PLATE? THE URL IS VERY DETAILED ABOUT THIS PROCEDURE AND APPARENTLY THIS PERSON HAD SIMILAR PROBLEMS...

You must have used a lot of heat to bring the yoke to a cherry red hue. I am at 50/50 on that you warped it.



Wow, you went Rambo on the yoke huh...

 

Pretty much. It was a royal PIA. Thanks for the link.

 

moans and vibrations are, in my experience, frequently the center bearing, and I most CERTAINLY would have replaced it and the rubber donut it sits in as part of any driveshaft R&R as it was already all apart.

 

I replaced everything under there: flex plate, grease boot, centering bearing, donut and spring. I just read the link that Analogies posted and realized that I may have installed the Guibo wrong. I am going to take a look as soon as I get a minute. I really hope that I didn't warp the yoke but there really was no other way to get the damn thing apart. No solvent at my disposal would touch that petrified grease. Maybe a chemical dip or something may have worked but I don't have time for that sort of thing. I made the cardinal mistake of relying on a neglected volvo as my daily driver. I have four vehicles in my yard a 93 850 wagon (no spark), a 74 142 (4 speed manual, not fun on the highway) and a 77 Chevy pickup (3 on the tree, also not a highway rig). If I warped the yoke it seems like the center ujoint would have felt tight or uneven but it moved freely through its range of motion with no binding.

Anybody out there got a used driveshaft for a 93 wagon with M47 tranny, if it comes to that? Real lack of bone yards around here in northern NH.

 

manual transmissions are pretty rare on 90s Volvos.

 

how is your dist cap or camshaft sensor on the 93 850? I had mine with cracks inside and caused a no start ....went days tinkering....all junk yard parts as these are common in my are.

that is true...a manual on a 90s Volvo is rare. If you do find a junk yard I would pillage the driveshaft from an older Volvo with the M47 set up or just a yoke.

 

I didn't realize standards were so rare on the late models. Why do you recommend the driveshaft from an older car? Didn't they have a different flange on the tranny tailshaft i.e. another u joint instead of the flex coupling?

The 850 has been a headache for weeks. My wife inherited the car from a co-worker who was the second owner. He's invested over 10K in the car over ten years of ownership. He started running into intermittent no start situations. His mechanic just started throwing parts at the ignition system as far as I can tell. The coil, module, rotor,cap, plugs and wires were all changed and still they couldn't get it going. He became so frustrated with the repair bills that wern't leading anywhere and decided to call it quits. He went out and bought a new tacoma and knowing that I was into Volvos asked if I wanted to give it a shot before scrapping it. i agreed did a quick search online for "850 No Spark" and got a bunch of hits for cam sensor. His garage had not yet replaced this part. I swapped it with a known good unit and it fired right up. Ran great for about two months and then just quit on the highway out of the blue. Have not been able to get it started since. It was throwing codes for cam sensor, speed sensor, TPS and some ABS codes. I tried a new TPS and still nothing. I get a healthy squirt of fuel from the rail with the key on so it sems that the fuel pump relay is working ( I understand that the fuel system has to be functional for these cars to create spark) I have read that a faulty speed sensor is not going to prevent spark so I haven't replaced that. The cam position sensor code may be left over from before and never cleared. I don't know. I've kind of had it with the overcomplicated systems in these cars. I don't want to scrap it but I also don't want it hanging around in the yard forever.

 

My cam sensor was cracked on the inside.....a small crack....I did the same thing.....plugs wires dist cap rotor speed sensor...and NOTHING...until I popped the cam sensor and realized it had a chip not a crack on the part inside that sandwiched the cam lip...for lack of a better description....it started right after replacing the thing....it drove super nice...mine was a turbo....I sold it as I had my 87 wagon...and loved the working space.

I crawled under an 83 wagon with the M47 set up...at a junk yard....what I meant to say was that you might find the M47 set up on other year car and pillage it all....

 

An 83 almost certainly had an M46, the 4 speed gearbox with the electric overdrive, similar to 1960s British sports cars (tr-4 etc). AFAIK, M46 and M47 cars have different length primary drive shafts.

 

I actually borrowed a working cps and swapped it with my brand new bosch sensor just to eliminate the possibility of having purchased a faulty sensor. Same thing, cranks with no spark.

 

Hello Pierce,
Could you please post a picture of the drive shaft with center bearing and attached hardware for a 1987 740 turbo wagon?

I am dropping the drive shaft tomorrow and plan on replacing the center bearing/bushing assembly. Possibly also the U-joints. Also could you give me a little instruction on how to know if the U-joints do in fact need to be replaced. When I grab the drive shaft and turn it by hand and move it around the U-joints seem solid. The drive shaft wobbles a lot at the center mounting, however. The U-joints aren't much money and if you recommend changing them just on general principle I will follow your recommendation. The car has 180K miles. Not much for a 1987, I guess, but they are Honolulu, Hawaii miles so not easy ones. Salty marine air, lots of starts and stop driving, many long steep downhills.

Thank you.
Sincerely,
Robert Booth

 

Check the U-joints for any play and binding. There should be no play at all when you try to rotate it. Also it should not bind at all when you flex it. It is easier to check when the drive shaft is off the car.

Just a note - Prior to removing the drive shaft, make sure you mark the front and rear shafts so they go together the same as when you took them apart since the two shafts are balanced as a whole unit.

Regarding the wobble - you might need to replace the center bearing carrier rubber boot. If there are any tears or cracks in the rubber then it probably should be replaced.

 

Hello Act,
Thank you for your reply.
Heading to the car now to drop that shaft. Glad you recommeded marking the shaft layout for later re-assembly. I wouldn't have thought of that, I'm sure.

Sincerely,
Robert Booth