Transaxle/motor mount again

[ArtBasement]

I am hoping for your feedback on some motor mounts I saw.

Back story: I replaced the original mount last year with an ebay mount (TRW brand) and it sagged and bulged almost immediately. Midwest sells a mount they won't recommend for the 1500 engine, so I bought a Vicks one. Seemed good, much firmer than the TRW, but after a few months this one is also making contact. I have about 1/8" clearance now. Today I saw this: https://classicperformance-parts.co...x-transmission-lower-bottom-adjustable-mount/ You can slide this up and down to get more clearance. Looks genius! What do you all think?

 

[Dr.Jeff]

I've looked at that one as well.

The available lower mounts have been an issue for some time now. I recall we went through a few discussions about how to improve them so it will last. Several great thoughts, most of which involve making a better version. But some ideas to modify an existing one as well. Oddly I don't recall the concept of moving the whole mount up (or down, depending on which way you look at it) being discussed. I thought I had one of those discussion threads saved but I don't find it now.

When I first saw the slotted mounting holes on this one I assumed it was for achieving proper positioning of the mount in general. Not necessarily to reposition the engine/trans themselves relative to the chassis. But to some extent it could do that, as you say.

Overall I think the biggest factor is having a better rubber (or whatever material) insert built into the mount. Moving the whole thing up or down seems more of a "bandaid" to overcome a lack of good support by the material. Perhaps the best solution would be a combination of both; a better cushion and some adjustment.

I suppose there are two ways to look at it. You could start with a better design mount (in terms of the material used) and then slot the holes. That's assuming you find a better mount. Or you can start with this slotted mount and try to improve on the material to offer better support. Some of the ideas discussed before can be done to help achieve that. Without some improvement in the design (i.e. better supporting material) I imagine eventually the rubber will sag enough that you will run out of 'adjustment' in the slots.

 

[Dr.Jeff]

Found the thread I was thinking of:

Lower Engine Mount Sources

Getting to be time for replacement again... No obvious signs of contact, but it’s definitely getting close Last one came from EuroSport UK, but every email I’ve sent in the past year, they say no stock, waiting... Anyone located another reliable source ?

xwebforums.com

Lots of good info there.

 

[Ulix]

I slotted the holes on a stock mount.
It does help a lot, but you have to tighten the bolts (and nut) quite tight to keep the transmission from sliding back down.
This tends to pull the aluminum threads out of the transmission. Not good.
Better to weld up the slots in the mount to reposition the holes.

 

[ArtBasement]

I've looked at that one as well.

The available lower mounts have been an issue for some time now. I recall we went through a few discussions about how to improve them so it will last. Several great thoughts, most of which involve making a better version. But some ideas to modify an existing one as well. Oddly I don't recall the concept of moving the whole mount up (or down, depending on which way you look at it) being discussed. I thought I had one of those discussion threads saved but I don't find it now.

When I first saw the slotted mounting holes on this one I assumed it was for achieving proper positioning of the mount in general. Not necessarily to reposition the engine/trans themselves relative to the chassis. But to some extent it could do that, as you say.

Overall I think the biggest factor is having a better rubber (or whatever material) insert built into the mount. Moving the whole thing up or down seems more of a "bandaid" to overcome a lack of good support by the material. Perhaps the best solution would be a combination of both; a better cushion and some adjustment.

I suppose there are two ways to look at it. You could start with a better design mount (in terms of the material used) and then slot the holes. That's assuming you find a better mount. Or you can start with this slotted mount and try to improve on the material to offer better support. Some of the ideas discussed before can be done to help achieve that. Without some improvement in the design (i.e. better supporting material) I imagine eventually the rubber will sag enough that you will run out of 'adjustment' in the slots.

I read all those previously as well. It seems sturdy rubber is hard to come by. I had even inserted more rubber into the holes in the rubber.

 

[ArtBasement]

I slotted the holes on a stock mount.
It does help a lot, but you have to tighten the bolts (and nut) quite tight to keep the transmission from sliding back down.
This tends to pull the aluminum threads out of the transmission. Not good.
Better to weld up the slots in the mount to reposition the holes.

Thanks for the feedback. I share your concern about the bolts and nuts. Now all the weight of the engine and transaxle in full bounce mode is resting on the bolt friction and not on solid metal part of the mount. Did your slots end up near the edge of the bracket?

 

[Steve Hoelscher]

I slotted the holes on a stock mount.
It does help a lot, but you have to tighten the bolts (and nut) quite tight to keep the transmission from sliding back down.
This tends to pull the aluminum threads out of the transmission. Not good.
Better to weld up the slots in the mount to reposition the holes.

I would expect this to be a problem. The vibration and torque would cause the part to move. And the mounting bolts are only spec'ed for 18 lbs/ft.

Those holes are frequently stripped. I keep helicoils on hand because the two rearmost mounting holes are the most common threads to be stripped. I probably have to fix at least one on every other unit I build.

 

[docpan]

I ordered one from Chris Orbet. Looks correct and is firm. No sag yet

Fiat Parts and Supplies

 

[7982X]

I ordered one from Chris Orbet. Looks correct and is firm. No sag yet

Fiat Parts and Supplies

View attachment 37041

Since you have a 79, guessing it is a 5 speed.....correct? Also, how long have you had the "Chris Obert" mount in the car (time & miles)? We are getting ready to re-install the engine & trans and would like to avoid having to replace the mount a few months down the road. We have an Allison custom exhaust, so don't need (or want) the long arm on the 80-88 mounts.

 

[docpan]

Its only been a week, it feels as heavy as the original. Yes a 5 speed. Only time will tell.

 

[lookforjoe]

The last one I bought was from EuroSport (UK). It's still good - I just checked, I bought it 10 years ago (!), so maybe 15K miles on it...

EDIT - LOL - I just looked at the thread Jeff linked - so mine was NG by 2018

 

[Ulix]

Did your slots end up near the edge of the bracket?

Yes they did, but that is not a problem. The weight of the drivetrain acts downwards and the holes are near the top edge of the plate.

 

[carl]

Is it possible to put washers between the cross-member and the lower mount to raise up the mount in relation to the cross-member?
As noted by others, there is no way I would be able to tighten those three fasteners enough to hold a slotted mount in place.

 

[EricH]

Is it possible to put washers between the cross-member and the lower mount to raise up the mount in relation to the cross-member?

The mount attaches to the underside of the crossmember, so it's already as high as it can be. Any spaers between the mount and the crossmember would lower the mount from there.

To be able to adjust the mount up, we'd need to attach it above the crossmember instead of below, but there's very little clearance between the oil pan and the top of the crossmember to arrange for mounting hardware.

 

[Dr.Jeff]

Ya, it can be a bit confusing when thinking about "raising" the trans/engine since the mount sits what you might call "upside down". One of the potential solutions I've considered was to make brackets that hang down from the crossmember/trans-engine to allow using a more traditional style trans mount - one the sits under the trans and over the crossmember (so to speak). The main reason I was considering this approach was not so much to raise its position, but to be able to use a different (more robust) type of mount altogether. Having one that the trans sits on rather than hangs from might help as well. However as Eric noted there isn't a lot of room there so this might not be possible (I haven't played with actually trying it).

After our previous discussions on this subject I came to the conclusion the better/simpler approach might be to try and make a stock mount more robust. I thought a combination of adding oversized inserts into its openings and filling them with a urethane adhesive, plus adding support plates to either side of the rubber might do it. But I'm not so sure. The next approach would be to make a complete urethane mount as others have done (see the thread linked earlier).

The issues about the slotted holes slipping and/or the threads pulling out of the aluminum case from trying to tighten the bolts too much sound very real. A mount with slightly repositioned vs slotted holes (e.g. weld up the existing ones and drill new ones) might work. Though I still think this approach is a bit of a "band aid" rather than a solution.

 

[Mxgrds]

At least the holes are positioned right. They won’t collapse by the weight of the engine.

 

[ArtBasement]

A mount with slightly repositioned vs slotted holes (e.g. weld up the existing ones and drill new ones) might work. Though I still think this approach is a bit of a "band aid" rather than a solution.

Just trying to get my thinking right way up: If I slot and weld or reposition the holes, I would weld red and slot yellow, correct? That in my mind would attach the transaxle higher. And currently I have about 1/8" clearance and it constantly bottoms out on bumps. How much clearance am I shooting for? 1/4" or more? Actually I think rewelding and completely re-drilling is easier anyways. And I'm not too worried about band aids, as long as they work!

 

[carl]

Sorry about my stupid idea, I should really look at parts before I make what appeared to be a way too easy solution.

 

[Dr.Jeff]

Just trying to get my thinking right way up: If I slot and weld or reposition the holes, I would weld red and slot yellow, correct? That in my mind would attach the transaxle higher. And currently I have about 1/8" clearance and it constantly bottoms out on bumps. How much clearance am I shooting for? 1/4" or more? Actually I think rewelding and completely re-drilling is easier anyways. And I'm not too worried about band aids, as long as they work!

I'm pretty certain you have it the right way. But without going out to look at it I won't say 100%. As you say, it gets weird looking at things upside down.

Think of it this way (pic below). An old mount sags in this direction (red arrow). So you want to move the whole mount in the opposite direction (green arrows):

As for how much to move it up, hard to say. Look at how much your old one sagged, and compensate that much. Or try jacking the trans/eng up to see how far it has to move to get a good clearance over the crossmember. That might also allow you to see how far you can go up before other issues occur (e.g. go too high and get interference elsewhere).

I'm with you, I'd rather weld the holes up and redrill them.

Please document and report on what you find, I'm sure we can all benefit from it.

 

[LarryC]

OH I have thought long and hard about this over the years. Had I the necessary welding skills this is what I would do. Flip the mounting plate. You will notice that the center stud is not in the geometric center of the mounting plate. Some have speculated that the factory accidentally mounted the plate upside down. Just this little amount gained would be enough to make us happy. Someone should do this and sell them.