'95 SL1, 341,000 miles.

When changing my oil earlier this evening, I noticed a couple of things about which I'd like to get the opinions of the folks here.

The first is the condition of the motor mounts. The mere act of twisting off the oil cap with my hand, with everything turned off, made the driver's-side end of the engine wobble about its pitch axis by about an inch, and I don't remember it ever being that loose before. My oily notebook tells me that one motor mount was replaced in 2015, but I seem to have lost the papers for that repair, so I don't remember which motor mount. How many motor mounts does this car have, and how do I know when it's time to replace them?

The second is the condition of the sub frame. The rust, unavoidable in this part of the country, now has gone all the way through in one spot, right behind the left front wheel (see photos). In your opinion, how long do I have before I really, really need to go visit a junkyard in a warmer, drier climate to pick up a new(er), non-rusty sub frame? And, how much can I expect to pay for it?

Thanks for your thoughts.

 

Going to guess that the previously replaced mount was the upper torque axis (passenger side) mount. They take the biggest beating by far and are kinda considered a maintenance item. People test them by symptoms (excessive vibration in the cabin and under the hood in general), too much jumping around under the hood, and specifically too much rotational motion under throttle. Physical evaluation may find that the rubber of this Mount is torn loose from the surface on which it is attached. The basic rule of thumb, however, is that if you can fit a number two pencil between the rubber block and the upper support portion of the mount, the mount needs to be replaced. The OEM ones which are long gone used to last about 100K. The aftermarket crap last I don't know how long because I can't stand it in my car and I use an old OEM one that is past its peak.

The lower torque access mount is easily seen as a dogbone mount at the right front lower corner of the block. again, you are looking for excessive play, torn rubber, and rock hard rubber, as rock hard rubber no longer has its elasticity and there are four provides no real vibration isolation.

The dog bone on the driver's side is more for positioning of the engine. It does not dissipate a lot of energy. The remaining mountain is between the transmission and the frame, obviously known a transmission mount in the form of a rubber block with a metal backing. This again also take a beating but I usually replaced. Again, torn rubber, excessive engine movement are the symptoms. Excessive vibration in the cabin usually will buzz on the dashboard or some part of the vehicle closest to the firewall. I'd say after we will assume $170,000 miles. You're two for a new top one. Make sure to use new nuts and studs , as the studs will wear slightly from the vibrations and used ones will therefore not be as they should be.

Use a torque wrench or pay the price. The torque is something in the low foot pounds. If you are going about your Merry way you will twist the stud right off.

I would replace the upper dark axis mount along with the studs for it. Be sure to support the engine properly before releasing the mount. Directions for that are all over the place.

 

With respect to the subframe rust, that is in fact the most common place for the S cars to rust out. That looks pretty nasty. Truly hard to say for me whether I would feel safe driving it. There is a lot of stress on that end of the control arm while driving so the attachment point needs to be structurally sound. I'm going to guess you have issues when trying to do alignments.

A used subframe is not really expensive. Transporting one is. Unless you have a pickup truck with a good gas mileage, it costs quite a bit for shipping let alone the actual subframe.

 

Thanks, derf. I found two of the mounts. The one up top, between the engine and the coolant reservoir, I can indeed stick a pencil between the rubber and the bracket, with room to spare. The one under the transmission looks.....okay, I guess. What do you think of it? (Pictures below)

As to the sub frame, I'll start casting about for one soon. If I find one not too far away, I can go get it on my next weekday off, whenever that is. A few years ago, I strapped a junkyard find, a car door, to the roof and drove it 300 miles home at 45 miles an hour, so no worries there. If it's much further away, though, I'll have to have it shipped.

 

Tranny mount looks somewhat worn. I'd replace it.
Cheaper to buy a full set I do believe.
I used the Mormounts ? From RockAuto. May be cheaper on Amazon.

The tranny mount can be replaced by removing the upper mount, continuing to support the oil pan with wood between the jack and oil pan, and lifting the engine just high enough to almost get the mount out. The rest of the needed separation is obtained with a crow bar and a friend. There is just enough room to get the old Mount out in the new one in. I've done this more than once. Just don't punch a hole in the oil pan because you didn't distribute the weight/force across a piece of wood.

 

I don't know where you live, but there's two 97 S series cars on the Birmingham, AL lot. Here's a link to them. Both are the gold color. One has been there since March and the other one has been there 6 days. https://www.pullapart.com/inventory/...onID=0#results

 

Thanks, guys. I had been looking at some in Alabama, Arkansas, and Oklahoma that might do the job. None of these are that close, but they're doable.
I think I'm going to tackle the motor mounts first.

 

Motor mounts aren't going to fix that rust. You're going to need another sub frame if you intend on keeping that one on the road. Trust me, a sub frame is going to be a hell of a lot cheaper than another car with years of payments. A few hundred dollars and a one time payment or 6-8 years of payments? I KNOW which one I'd do, but I'm a poor bastard on a fixed income. It sucks.

 

Oh, I'll replace the sub frame, I've got time off work coming next month, that will be a good time for a junkyard run.
The mounts, I can take care of them this weekend.

By the way, my profile picture appears on my profile page, but not on my posts. Is there a setting I need to change to fix that?

 

This thing must be in very nice condition to put all the work and money into it. The rails will need to be done as well. You basically need to build another on top of it.