Question on motor mounts, 1971 fj40 (1 Viewer)

[sproggy]

Ok I'm back to messing around again with the truck. Since I don't live any longer in the same place where it resides I don't get a lot of chances to work on it or drive it. Anyways.... Since as far back as I can remember (I've had the truck for 30 years now) it has always shaken and staggered a bunch when starting out in first gear and then smooths out. I always thought it was clutch jutter and never did anything about it. Well, now I'm thinking it is loose or broken engine mounts and I'd like to do something about it. The two front mounts seem to be ok. The rubber in the back two is quite shredded, however, and in fact I just pulled a big piece off of it as it was just hanging there doing nothing. Even weirder, I think, is that each mount has about 10 galvanized steel washers used as spacers on the bolts. This doesn't seem normal. The drivers side bolt (the one through the frame) seems to be at an angle, slightly rotated toward the passenger side of the car. Is that normal? The frame is also bent just behind the engine on both sides. I didn't give it much thought as a kid but now that I have a hopefully better head on my shoulders I'm thinking this truck must have been in a serious enough head on something-or-other that bent the frame and shredded those motor mounts. It still drives and I have even done plenty of highway driving on it back in the day so the bent frame and questionable motor mounts, while far from perfect, don't cripple the truck.
Any advice on these motor mounts? Do they sound normal? Might I replace them or am I going to wind up not being able to get the motor back on…since the whole alignment might be screwy. The drivers side mount…it hardly seems possible to access it with the tub on the frame. I have read some info on here about jacking up the engine under the oil pan…and slowly loosening the mounts as you do it.

Well, any advice appreciated. Thanks and cheers, Sproggy

 

[honk]

If you have a block of wood and a floorjack you can resolve all this "seems to be" and "I'm thinking" by jacking the engine up until at least one front wheel comes off the floor. If those front mounts are broken, or either one is you'll know it.
Do the same near the rear mount.

If the jacking tears the rubber on any of the mounts it needed changing. Don't go around thinking that you broke it.

And take the truck to a frame shop. A good shop has these neat tools that can bend a frame back to straight, while you wait.

As far as not crippling the truck if the mounts are marginal, think about driving down the street and coming off a stop light when a hellacious noise happens. You open the hood to see your engine lying on its side and all fluids coming out from everywhere. It has and does happen as worst case.

 

[sproggy]

You mean put the jack under the engine and jack it up, correct? What do you think about my description of the flat washers on the rear mounts? Is that normal? Looks pretty near impossible to access that front driver's side mount. How the heck to I get in there?
I always thought bringing it to the frame shop would cost me an arm and a leg and have little effect but this was 20 years ago. I guess things might have changed. I will look into it, thanks for the advice.

 

[honk]

If the frame is bent, and bent badly enough, it'll take your whole driveline out of alignment fore to aft. That would make for vibrations, broken parts, and eventual gross failures. You really need to find out if it's bent and if so how badly bent it is.

No one here can advise you very well without being able to look at and drive the truck.

An inspection won't usually be too expensive. A good shop can tell you the state of your frame with their estimate for repair, but you can have them stop right there and give you a copy of their findings.

 

[sproggy]

Thanks, honk. I'll take your advice and get it looked at, at least. I have driven 1000s of miles with it like this so....well, who knows? I suppose anything can happen and much better to be aware. I'll be in touch. I appreciate your time.

 

[Coolerman]

Here is what a rear mount on a 1971 FJ40 SHOULD look like... I would replace all of them. It's easy to do, but plan to cut or twist the bolts
off. They will be seized from rust.

f

 

[sproggy]

Wow, amazing! This is a pic with the tub off? I don't know how the heck to access the one in the photo. And no, mine does not look like that. It is torqued toward the passenger side. I would take a picture but I don't even think I can get a camera in there. No wonder the thing shakes on take off.
So, any advice on getting at the thing? Or is it accessible with the top trans cover off? The other end of that bolt is inside the frame rail, and doesn't appear to even have a hex head on it...more like a rivet. Is that accurate? I couldn't see inside the frame rail, just felt with my fingers, but I couldn't feel much of anything. In fact, the whole thing is so rusted and chewed up, I couldn't even figure out exactly how it worked. I would love to fix it. I'm wondering if I'm opening up a Pandora's box if I start messing with it.
The front two mounts are different on my truck and are square.
Hmm, I see a washer on the top. Is there a whole stack of them like I have? I doubt it.

Thanks so much for the help...

 

[Coolerman]

Yes, that is with the body off. Removing the trans cover will make it a lot easier to get to but it will still be a tight fit. As I said prepare to have to cut the bolt off. This is where a torch comes in handy...

 

[Jdc1]

Taking the fenders off would help access as well.

 

[sproggy]

I just got new tires for it today and while it was up on the lift I got a good look underneath it: s***. What I'm realizing now is that it must have had a pretty hard front end impact at some point. The frame is slightly buckled on each side just behind the rear motor mounts, with the motor mount on the drivers side really tweaked. That is the frame buckled at the top right under the mount. It has risen up on the inside edge and angled the motor mount toward the outside of the car. In fact, I can't even get a wrench on the nut it is so close to the body of the car. Both rubbers are pretty shredded. As it is, I don't think I will ever get the motor back on to any mount without fixing that frame first. Other things I am noticing is that the impact slightly slightly skewed the front leaf springs I (they are not all stacked neatly on top of one another...the bottom springs twist out slightly to one direction on both sides) and slightly twisted the U bolts on the axles. You can see that the impact must have been more on the passenger side and threw everything on that side toward the drivers side. It must have been the weight of the engine and trans to buckle the frame at the mounts. It's really a miracle that the truck has been going all these years in this condition. Since it was always like this I never gave it much thought. This is far more involved than new motor mount rubbers.....

 

[Jdc1]

There is a change in direction of the frame right behind the engine. The body/chassis FSM has frame dimensions to compare yours to.

Post some pics and let the forum tell you their opinions.

 

[Living in the Past]

Mt 68 had a bad shudder after replacing the clutch. Company doing the work hadn't finish at the promised time and found someone in back rushing to adjust the fingers. This was with a four speed making it a royal pain to pull and set up correctly. I adjusted it thru the opening on the bottom of the bellhousing. That corrected the shudder. Motor mounts would be less likely to cause a shudder and more likely to clunk. If it were me I would try the pressure plate fingers .

 

[Jdc1]

Pics lifted from internets

 

[sproggy]

About the clutch, well that's nice to know. I put in a new clutch many years ago and I vaguely recall reading something about adjusting the fingers....after I had put the truck back together. I had assumed they were good to go as is so I don't believe I ever checked them. I didn't realize they could be adjusted with the tranny in. I will have a look/see tomorrow. That's exciting news. If I remember correctly, there are hex bolts on the ends of the fingers, yes? Would I need any special tool to get at them?

As for the frame, I'll try to take some pics with my phone tomorrow.

Everyone's help is much appreciated. What's astonishing to me is that coming back to the truck after 20 years away...so many things that seemed so difficult when I was much younger and working on it now seem so much easier. I don't know if that's because the internet is around to ask questions or because I somehow got "smarter" in regards to the truck. Not saying I'm any genius now but...

 

[Living in the Past]

Been many years since I had to adjust it but going from memory the smooth surface that rides on the throw out bearing is hexed. The fingers are threaded and the bolts use a nut to lock them in place. The measurements are in the FSM. Hard to measure inside the vehicle. I mainly made sure all three we as even as possible. Used a 12" 3/8" socket extention in holes on the pressure to rotate the engine.

 

[sproggy]

I'm excited to try this, Past. I'll report back...

 

[73FJ40]

The other end of that bolt is inside the frame rail, and doesn't appear to even have a hex head on it...more like a rivet. Is that accurate? The front two mounts are different on my truck and are square.
Hmm, I see a washer on the top. Is there a whole stack of them like I have? I doubt it...

The rear motor mounts are held in place with a long, hex head bolt, drilled for a cotter pin. No stacks of washers, just the normal complement. These bolts may still be available from Toyota.

Front mounts are supposed to be different, F engines have round ones, later engines have the square ones. The round ones can be replaced with square ones, but apparently the motor mount casting holes might have to be enlarged a little for a proper fit.

 

[sproggy]

So I got the plate off under the bell housing, snapping off two screws closest to the headers in the process, one which I will never be able to drill out without taking off the headers...anyway...now what? I can see the three fingers and spin the fly wheel by hand. They are all touching the throw-out bearing. Do I need to check these with the clutch pedal depressed?

 

[sproggy]

With the clutch pedal depressed...they are still all touching the throw out bearing.

 

[sproggy]

Hmm, re-reading your post I am now under the impression that the three spacer screws on the end of the fingers have the same measurement, meaning the distance between the head that rests on the throw out bearing and where the stem enters the threaded hole on the finger, yes? Mine are not even, that's for sure. So, tomorrow I will have a go at it....Strangely, the shudder is not always the same. Sometimes it is barely there. The truck seems to be friendlier in reverse i.e. less shudder.