Is this a tranny problem?

[z_johnq]

1991 Lexus LS400. The car has about 180k miles on it.

The car starts fine. Basically idle is fine too but I can feel very minor miss as putting my hands at the tail pipes of the muffler. But as driven, when doing around 45 miles/hr to 50, the steering wheel starts to shake and so does the gear shifter. It feels like the suspension is about to break. But as I downshift to D2, it feels just fine. But the RPM goes sky high, which should be normal.

I checked the tranny's fluid, it's pink and no odor of burning. I also checked the plugs and the ignition cable, nothing is suspicious. The water pump and timing belt are about 2 years old.

I guess the tranny's life is almost up. What would you guys think?

Thanks in advance.

[Exhaustgases]

If doing 45 to 50 and if you put it in neutral what does it do then?  Shake could be bent wheels or a goofed up tire.  Also when driving it use the OD button, try turning it on and testing then turn it off and see what it does. Its not easy to guess at a problem when a person is not in the car feeling it.

[z_johnq]

Thanks for replying. I did not try OD button on and off. I did try shifting to D2. It got much better and almost no shaking. I checked the web around. Someone mentioned that it might be the problems with tranny mount, which probably turned bad and needed replacement. Can I check it by the looks or I need some tools without taking them off? Please advise.

No, there are no bent wheels since there was no accident lately. Thanks for the reminder: I will rotate the tires to see what happens, even though I doubt they have something to do with the problems. They are not new tires but in pretty good condition.

[landar]

Most likely just the mount. It is fairly easy to replace and prone to going bad. So I would advise to just order a new one and replace.

[z_johnq]

Sounds the right thing to do. I checked RockAuto online store and they do carry them. But before I do it, let me rotate the tires first because I found a not-too-big bulge on the wall of one of the front tires. Probably comes from hitting pretty hard on a pitfall or something. 

One more question. My 95 LS400 has a cracked EGR pipe (lower part). It's extremely hard to take it off and replace because the gap between the pipe and the tranny is too small to get my hand/wrench in. If I take off the tranny mount, can the tranny be lower slightly so I have more room for my hand to reach the pipe?

Thanks again in advance.

[Exhaustgases]

Yes, and keep an eye on the engine hitting anything on the firewall. Some people have had the crack welded probably cheaper than a replacement. I'd do the new part and keep the old one to fix later for a spare.

And a tire blister is likely the shaking cause, and maybe both the mount and that are working together.

[z_johnq]

Thanks for the tip Exhaustgases. My 95 LS sat in my garage for about 2 years because of the problems with the EGR pipe. I tried quite a few ways of reaching the pipe (mostly from under) but failed. I had been busy so left the car alone. 

Yes. I can weld. I have MIG and O/A equipment and more. I replaced part of the exhaust pipes for my 96 Land Cruiser and some welding involved (the replacement of the converter (bought from Ebay) had no heat shield; I found one and welded on top of the device). I guess MIG should be fine. I'll keep you guys posted.

[z_johnq]

One more symptom I'd like to tell you and I suspect it have something to do with the shaking. When it's cold and start the car in the morning, I cannot turn the steering wheel until it's warmed up. It feels like it gets stuck. Is that a problem with the rack & pinion? Sometimes, I cannot wait so I turn hard to break loose. It may hurt the system too.

Thanks.

[landar]

To me it sounds like it may be a sticking valve at cold temps. Have you ever changed the PS fluid or cleaned the filter?

[Exhaustgases]

It could be what landar says and it could be a small screen that gets plugged on an electrical valve that is down on the rack assembly near where the steering shaft is.

The valve threads into the rack assembly, and after it is out the little screen is obvious, you can only clean it as the dealer does not sell them.

[z_johnq]

I didn't even know there was a filter for PS pump, or a filter close to rack & pinion. But I'll check it out. The point is if it can cause the shaking I was talking about. I just suspect.

Thanks.

[Exhaustgases]

The PS pump has no filter, it is a screen that you can see in the reservoir floor after you suck the fluid out with something like a turkey baster or battery fill bulb. It seems to get a lot of junk that looks like hoses deteriorating chunks that can plug it up some. And then that small screen on that electric valve on the rack.

[landar]

A screen is a filter. Just filters larger particles. 

[z_johnq]

Thanks for the explanation. Let's leave it for now since at least I can let her warm up and free the steering wheel.

I tried to fix the shaking problems. As I jacked up the front end with the right wheel above the ground, first I checked the tranny mount visually. It looks fine: the rubber sort of soft and elastic. Of course I will take it off to check further. Guess what I found:

1) the brake was stuck: it was almost impossible to turn the wheel with hand; something wrong with the brake for sure. Long story short, the piston (one of them) did not move at all in the caliper. With a C clamp and brake pedal, and some brake cleaner, it got pushed out and pressed back in a few times, it's getting better. With the wheel on, as I turned it, still feels some drag but at least it can turn now. I guess I need to replace or rebuild the caliper(s).

2) the upper control arm has problems. With the wheel above the ground, I held the top and bottom of the wheel pushing it in and out, I heard clear sound of metal contact. The clearance is not tiny. I found the problem as I bought the car 9 years ago and did not want to replace it with the cost over $300 the part alone.

3) a small piece of hard rubber torn off from the shock probably from the shaking.

Not sure but the shaking mainly comes from the stuck brakes. But I guess so. Let me checked the left brake and keep you guys posted. Thanks again.

[z_johnq]

Do I need to take the PS off to clean the screen/filter or leave it on the car and do the cleaning?

[Exhaustgases]

Leave it on, I have not yet removed one but having the correct tool would be nice, since I don't like the idea of using a punch and hammer to do it.

As far as calipers. If you have a good place to do the work and time then yeah do the rebuild, the way I usually do that sort of thing is get replacements at Oreillys or Napa

or ? and makes the job happen faster. Then in my spare time do the fix on the old ones and then you have spares.  I'd get the repair parts from an online source as they will be cheaper than a local autoparts store.

[sha4000]

If your going to rebuild the calipers I suggest you do them all at the same time. I had a stuck piston  on the passenger side this past summer so I ended up buying new front rotors and pads all around as well. The rebuild kits are really inexpensive, probably like $20 for all 4. The hardest part is getting the seals back on the Pistons on the front calipers since the space is tight in there. 

[z_johnq]

Hi guys,

Thanks to you guys' help and ideas. I got the problems fixed. I was in a hurry so I did not rebuild the calipers: just replace the brake fluid. Still have some drag as the wheel jacked up but I think I can live with that. I tested drive for an hour on freeway. There was no shaking at any speed range. After came back, I felt the front wheel rim: slightly warm. I guess I can live with that too. I'll rebuild the calipers anyway but not now since it's cold in my garage.

I also fixed the right upper control arm on the clearance of the ball joint. I injected some grease with a grease needle through the rubber anti-dust. Now, it's full of grease and unable to feel the clearance at all. I know this is a temp fix but now it's just a makeshift.

Haven't got the chance to fix the PS yet. At least it's drivable now.

Thanks again for your help! I'll remember the tips of rebuilding the calipers you provided.