Hello, brickers!

I finally got free time enough to breathe (and give myself tennis elbow in my dominant hand in the process). So I draine a couple quarts of ATF from my transmission and pulled the extension housing off my 1990 740GL to replace its output shaft bushing. I was trying to fix a horrible vibration for like 6 months with this thing.

The old bushing was pretty trashed and the driveshaft shop re-checked the balance. They straightened a portion that they had missed before, but I figured that the parts were cheap, so I would prefer to change out the extension housing bushing while the driveshaft was out. The bushing was the original volvo bushing and it looked like most of the damage was from corrosion from a failed seal.

Once I put the new bushing in (poorly), I left a few burrs along the top of the new bushing. I tried to clean them up and the flange goes right into the first half of the housing without issue. Then it binds up once it's about halfway into the bushing. (This is when I gave myself tennis elbow by straining to pull the flange out of the new bushing). I looked at the bushing and it looks out of round. There is a seam on the new bushing and there is a channel where fluid flows to reach the flange. The edges of the channel seem to be pushing the new bushing out of round and in towards the center. I'm going to have a machine shop work on it, so I will ask them to check the centering of the housing and check that it's actually round.

Has anyone notice this on a bushing before? Maybe I got a bad casting or was just too rough when putting the new bushing in?

I'm starting to think this 740 is cursed... anyone want to buy it? Half joking, but I don't plan to keep it past next year - 89 wagon should be up by then. Portland Oregon if anyone is interested.

Happy bricking!
Will

I have nothing to add or suggest, but how did you install the new bushing? Was it pressed in or driven in by hand? What did you use to bear against the new bushing to install it?

Randy
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Any twenty minute job is just a broken bolt away from a three day ordeal

I hammered it in with a socket (24mm?) that fit fairly well.

That was the wrong move though. In the process, I deformed the new bushing in an odd way.

I just got it back from the machine shop and the new bushing went in for them without issue.

Putting the bushing in the freezer and heating the housing may have have helped it press in easier.

Did this job a long time ago on my 90 240. If I remember correctly the old bushing warps causing the seal to leak. It is the warped bushing that causes the vibrations. Is your new bushing an OE bushing? Let us know what the shop says about the housing but my money is on a bad bushing.

Regarding your tennis elbow. Have some experience there too …:) I’ve had it twice. Both times in my left non-dominate arm. Once, many moons ago due to too much weed whacking at work when I was a kid. More recently, got it again after I broke my two forearm bones in my right wrist, then later had it rebroken and had my wrist reconstructed. Needed Carpal Tunnel surgery too due to the damn fracture. Needless to say I was very dependent on my left arm for a very long time. Trying to shovel snow with just my left arm did in the elbow again …:( The good news is it cleared up on its own both times. Bad news is it took at least a year. It does gradually get better. Suggest getting an elbow brace to use when really stressing the elbow. They do make a difference. If it’s really bad, consult with an orthopedic upper extremity specialist for their prognosis.

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Will I buy another Volvo??? We'll see....

In this case, it looked like a bad seal let water (and maybe deicer aka salt) into the bushing. It was etched and worn quite a bit. The groove in the new bushing showed that probably 60 percent of the bushing material was gone from the old one.

I think I buggered the new bushing myself. I ended up buying 2 more new ones and told them to just cram the new one in and see if it was something I did. It was. The new bushing is fairly tight, but it does fit and the output flange/shaft spins freely.


On the tennis elbow issue... I'm not sure what this is exactly. It was just quick and dirty diagnosed by an FNP (I have low faith in this level of provider due to several past experiences). I wonder if it was building over time, but it felt fine all the way up until I tried to twist the output flange out of the housing like I was opening a big jar of pickles. And then all of a sudden, BAM I hurt myself. That is some really bad news. I've been off work a lot so far this year between covid and RSV and now this ... the good thing is I think I could use a mouse. I'm about to finish a MS in materials science engineering, so I should be ready for a job change pretty soon. Hopefully at that point, this will be less of an issue.

The thing that has me worried is that my elbow has been stiff the last 2 days - I can't fully extend it without pain on the back/outside of my upper arm. That part is a little more worrisome.

Did you have to do physical therapy or did you just sort of try to return to normal use and eventually it healed?

Several decades ago I developed tennis elbow from the repetitive motion of hard scraping the inner fenders on a car I was preparing to paint. My wife encouraged me to see a doctor about it. He set me up with ultrasound treatments.

I'm not sure if it was the treatments or just time but I haven't been bothered with it reoccurring.
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Any twenty minute job is just a broken bolt away from a three day ordeal

Hi,

I would have to say that the ultrasound treatment had nothing to do with removing tennis elbow.
I say this because the sound waves are of such a nature or frequency that they are not like a microwave and vibrate the tissue to cause warmth or at least any that I felt.
I just had some swollen limp nodes under my arm pits done. So if anything the gel they use would cool it but I bet it’s for a conductivity medium.
I received my invoice on that procedure @ $593 a side. That’s a lot of court time money, gone, just for playing tennis. 🤓
The hand held device is a transmitter and receiver that’s tuned for short distances but is like radar.
Neither are a looking glass but probably close to the same principles.
The images are rather ghostly, at best but the words benign are getting tossed around
An oncologist appointment is next for special blood test. I’m actually thinking I eat too much saturated fat to keep my diabetes down triglycerides jump. So it one or the other nowadays.
I’m on the shuffle board of a testing brigade routine, to see what slides where?

An aching joint is from inflammation or irritation.
A bearing goes bad if something gets into the mechanism like dirt or there’s a failure of the bearings material it’s made of.
It appears to be that a plain bearing being used in that location will suffice for some time if the forces from the driveline is kept to a minimum. The universal joints are always throwing a load out radially so it’s a matter of time the bearing submits.
This is “Similar to out joints” except the bearing doesn’t have a sensory system to say, “Hey, that’s to much of that!”
Our body are self healing machines, up to a point. Just like things we build, we all abuse its limited boundaries too.

I think I have read somewhere that the design was changed to a roller bearing. I hope it was my 1992 as it’s my only automatic transmission Volvo.
It is also my understanding that these transmissions are also used in Toyotas. If you need parts they may carry some different numbers for the same thing that Volvo doesn’t.
Toyota or “Aisin” made just a FEW more transmissions than Volvo ever used.

It is sort of mandatory that to push bearings of any kind that it be pushed straight and evenly.
Preferably with a materials equal to of softer the the bearing material.
With the shaft out as it was mentioned the alignment has to be watched closely and since it was bronze a hardwood block or plastic is best.
You want something that defers indirect impacts to the bore.
Remember that baseballs don’t always go straight off an angled bat and so a in saying, a bearing doesn’t have the whole stadium to go into.

If the shaft was still there, as it may appear it should have been to make the repairs in a car, then a sleeve of aluminum or soft tubing steel should be machined to slip down the shaft and align things.

A slender stick Hardwood can be used if you are a woodworker type mechanic. 🙃
Just got to think with a “grain” of common sense. 🙂

Phil

It is my understanding that the AW transmissions in the Volvos used the bushing through the 92 models before switching to a ball bearing in 1993. Some time ago a Brickboarder asked for help in locating a replacement ball bearing for his Volvo. The last I heard he had been unable to source one.

One of our 940t has 317K on the clock. The last time I was under it there was no lateral play at the flange. I haven't noticed any vibration or noise that would lead me to believe it is excessively worn.
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Any twenty minute job is just a broken bolt away from a three day ordeal

Hi

I haven’t noticed any issue with my 1992 either but I’m on 275k.
A previous owner may have had it gone through as the Wagonmeister suggested prior to his refurbishment.
So we both have had good luck without any debris getting into those bearings.

I suspect it has a lot to do with good maintenance of the transmissions oil and the level being up high enough to get to those linear oil grooves in those plain bearings.
A power steering pump uses the same system inside. It all stays well if the oil is clean and fresh in them.
Helps to not run the belt super tight either.
Just make it where you cannot slip the pulley under the belt by hand.

Most steam turbines turning todays electric dynamo in our power plants run on plain bearings.
Anti friction roller bearings are not the most precise item in the design shed as they have to have clearances to be able to rotate. It’s all about oil flowing for support.
I have read journals on how the oil stacks up underneath on one side around the shafts lifting it.
There’s a bit of gravity and other physics involved within that engineering job.


Keeping the U-joints working smoothly and the shafts supported goes a long ways to that end.
I could suggest that the person who needs that particular bearing go by its size rather that a dealer or warehouse part number.
In some case changing the classification of fit tolerance or seals gives up a replacement unit at reasonable costs.
I wonder if the actual rear case changed to accept a thicker diameter ball bearing?
If they tried to work around that the differences would speak volumes about what caused the change and if it went on up into the 900 series to justify the tooling costs.
I don’t have manuals for those cars. Need more research.

Shifting gears here: 😋
I wish I could find time get into my two five speed transmissions to measure them out.
That’s a project you shouldn’t stop and start on.
Lots of Research is involved here as well.

I’m curious if I can find out what makes them fail with noises so early.
The best indications I can study, with on line information, is that on the counter shafts uses a tapered wheel spindle bearing on each end.
That makes sense to me that maybe the case, being made of aluminum, has expansion characteristics they causes a loss of the minor preload for them.

Specifications can change greatly in that style of bearing besides their quality too.
The evolution of a tapered design was like popcorn needing some salt and butter with limits of each.
I have played with areas where I could find movement to modify things in a few places in my lifetime.
With these 240 Volvos they have shown us how tiny changes can sneak in through the years too.
1993 has a rounded tooth timing belt and oil squirters.

I’m curious of why not a variation of an angular contact ball bearings being used instead?
Since they have to involved shims in either case.

The upper input shafts of the transmission runs at different speeds most of the time.
The main input bearing affects the whole thing backwards and down onto the layshaft.

The retaining ring on the outer diameter has been interesting to see too.
Maybe there are rpm limits I haven’t thought of or its that money thing being a factor.
Similar to the tail shaft of the automatic.

I have a M46 with a noisy one as I hear it only in neutral.
These later gear boxes are built on the predecessors design with the gear case being changed to aluminum let alone better synthetic oils to prevent spalling.

Oh well?

Phil

So the bushing is in and all is well?

Yes, both times I resumed my normal activities with the arm as the pain allowed. During the most recent bout of tennis elbow I bought a $10-15 elbow support at Wally World. Used when working the arm - definitely helped with the pain.

No physical therapy. Did have my wrist surgeon look at it when I was in to do a follow-up after my wrist surgery. He confirmed it was tennis elbow. He diagnosed it simply by pressing on my arm. Guy knows his stuff! He recommended a support or brace as needed. I only had pain. Don’t remember any serious stiffness or swelling. In your case, I would consider seeing an Orthopedic. Preferably an upper extremity specialist. At the very least try to get in to see an Orthopedic’s PA. They would know more than an FNP.
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Will I buy another Volvo??? We'll see....