Have been having a difficult-to-diagnose (for me, anyway) problem with my 1991 740 Turbo wagon. Here is what has been happening over the past year, and I'll try to keep it short and to the point. Would very greatly appreciate any help or ideas you can provide as I am lousy at diagnosis.

A year ago replaced left front tire because it had a bubble in it. There was also a great deal of wear on only the outer edge of the tire, somewhat scalloped. The steering wheel also shimmied or jiggled back and forth about 1 inch or so. Putting a new tire on seemed to fix everything. However, I had a gut feeling it was not really fixing the underlying problem.

Slowly, over the past year, the steering wheel shimmy has returned and progressively gotten pretty bad. The whole car shook with it at times. The new tire is now fully worn out on the outside edge of the tread. It is also scalloped like the one it replaced. There is no bubble this time.

Because I am so bad at diagnosis (and I have read the 700/900 series FAQ for steering and front suspension), I took it to a local Volvo mechanic, not the dealer. He said that the problem was the tire, and swapped it with the left rear (they are directional tread and he could not cross-rotate them). He was wrong. On the way home, the steering wheel shimmy was there as bad as ever. The car does not shake as badly, but I think it is because the old, scalloped tire is not on the front contributing to the problem. But, the tire that is there will soon wind up scalloped.

The mechanic claimed that he put the car on a rack and pulled and pushed, etc. the tire/wheel and that my ball joints/bushings/tie-rod ends are all fine. But I think he is wrong (and possibly an idiot). Something other than the tire has to be making the wheel shimmy, and causing two tires in succession, at the same corner of the car, to wear exactly the same way: outside edge wear only, with scalloping or cupping. Kind of sawtooth wear, but much further apart than saw blade teeth.

Am I right, and should I just methodically work through the diagnosis in the FAQ. And any extra insight or refinement to the diagnostics that you can provide, I would love.

Thanks
--
Scott Cook - 1991 745T, 1985 RX-7 GSL-SE, 1986 Toyota Tercel (Don't laugh, it is reliable, faithful AND gets 41 mpg!)

Update:

The "bad" tire was worn down to the belt cords in one spot, so I took it to a tire dealer yesterday and got a cheapo used tire put on to make it safer until I diagnose/fix the underlying prob. and get all new tires.

While it was at the tire dealer, a Goodyear tire center with a good local reputation, they were nice enough to have their alignment/suspension mechanic look it over for me, in detail, and for free.

Findings:
He kept pressing me, questioning me whether the bad tire had ever been on the back of the car. It had not. He kept asking because, in addition to the outer edge wear mentioned above, it had at least one big diagonal swath of wear clear across the tread. He said this is typically found on rear tires and is an indication of wheel tramp (up and down) due to bad shocks in the back. Not usually found in the front.

Joints/wheel bearings:
He also noted that the right tie rod end was beginning to show a very little looseness. Note that it was the LEFT front tire with the wear problem. All other rod ends, ball joints and wheel bearings were fine, good and tight. Left ball joint boot beginning to crack/split.

Bushings:
The sway bar bushings are completely shot, and I must assume that if they are shot, so are all the others under there.

Struts:
And, finally, the right shock strut is leaking, and he says they both look like the original ones (i.e. 16 years old, and over 250,000 miles).

My Analysis:
The right strut is leaking because it still has some strut juice in it to leak. The left one, where the problem is, is probably bone dry inside having leaked out ages ago. All the bushings are shot. But, thank heaven, all the joints have survived so far (I probablly will replace the one that is beginning to go loose). In that light, the problem really does seem to fit the diagnosis of severe wheel tramp due to completely shot struts, aggravated by completely shot bushings.

Now, if any of you have any suggestions of where to get good, high quality front struts for this car (1991 740 Turbo Wagon) at a reasonable price, I'd love to hear from you. Also, can the struts be rebuilt? The ones on my RX-7 can. This would save some $$$.

Thanks.
--
Scott Cook - 1991 745T, 1985 RX-7 GSL-SE, 1986 Toyota Tercel (Don't laugh, it is reliable, faithful AND gets 41 mpg!)

Do this work and you will be all set. All the work can is outlined in the FAQ section with terrific directions for each. You will need some serious tool though and a good jack with jack stands. Or you can pay a Volvo dude $1,200 to do the work for you. I use FCP there are a lotof folks on the board who are as please with FCP but I have good experiences.

Suspension Vendor "Part Number" "Price Each" Req'd "Total
Price"
Front Struts FCP PNE-3054-BE $58.00 2 $116.00
Front Strut Mounts FCP 1387188 $47.00 2 $94.00
Front Strut Boots FCP SB102 $15.00 2 $30.00
Ball Joints FCP 270477T $32.00 2 $64.00
Strut Bushings FCP ??? 5.95 2 $11.90
Total Front Suspension $157.95 $315.90

Check the FAQ's Front End section before you write off ALL the bushings, chances are you may only need control rod bushings in addition to your sway bar ends, especially if the alignment guy didn't notice anything amiss.

I would go at least that far if I were going to spring for struts and an alignment too. Ball joints and all four tie rod ends will add basically nothing to the bill once you are doing the struts, so do it all.

You will be amazed at how your brick drives.

Shifted

Have just read the FAQ again, and looked at IPD prices, then FCPGroton again. Oops, prior to making the last update post, I thought I had to buy the whole strut assembly as per FCP's "Suspension" price list. Have found that the insert is available at substantial saving, and the FAQ lays out the whole procedure nicely.

Will begin acquiring and stockpiling parts, planning on early April weekend job.

As per Shifted's thoughts: "Ball joints and all four tie rod ends will add basically nothing to the bill once you are doing the struts, so do it all." My thoughts exactly, including all bushings.

And, even coming from driving sports cars most of my life, I'm already amazed at how well this car handles (it was a lot better 3 years ago when I bought it), and moves. Especially for a car that can easily carry my whole family - 3 humans and 3 Great Danes!

Then there is build-quality, many mountain ranges are not as solidly built as these cars. Love this thing.
--
Scott Cook - 1991 745T, 1985 RX-7 GSL-SE, 1986 Toyota Tercel (Don't laugh, it is reliable, faithful AND gets 41 mpg!)

Remember that all of the front-end bushings other that control rod and sway will have to be pressed in, so don't forget to line up some machine shop time while you have everything apart.
A case of beer will probably go a long way to getting a whole front set done on a Saturday afternoon!!

Shifted

That sounds like a text book alignment issue. Go to Firestone spend 115 buck and get a life time alignment. That WILL solve the issues!

Andrew

I agree. It sounds like your left wheel is out of alignment.

I still think it's a good idea to rebuild the whole front suspension as suggested by others -- no sense in improving/correcting the car for it's next owner.

When you finish all that front end work, you'll be getting an alignment anyway, so you should be all set.

Jeff Pierce