Motor Mounts

[Greenbomb]

'50 Plymouth Coupe: I'm going to send my motor mounts to Steele for rebuild. The shop manual has a cross section drawing of the rear mounts and it shows the rubber like it protrudes down into a hole in the top of the crossmember, which it does. It shows a round piece (steel) that is below the top of the crossmember and between the top of the crossmember and the large flatwasher and nut that holds it all together. The round steel piece has an "L" cross sectional shape. The drawing is such that it looks like the rubber goes down and is form fitting to the steel ring. But, when it all came apart the steal ring is stuck to the crossmember, and doesn't want to come loose. I pried on it enough that if it was just stuck there because it is old crunched up rubber it should have come loose. It feels as if it's part of the crossmember. I just want to be sure I'm sending all the neccessary stuff to Steele. Sorry for the bad description, but maybe if anyone has done this it will make sense.

Also, before teardown, the transmission (3 speed stick) would pop out of 3rd gear just cruisin' along. The right rear motor mount has no rubber left on it, the left one is pretty flat and the front mount rubber is compressed down and to one side a bit. Could this cause misalignment/binding that would make the shift linkage be out of whack enough to either not allow it to shift all the way in or to put pressure on the linkage so as to pull it out of gear? Any help/info is appreciated.

Edited August 26, 2011 by Greenbomb
Note this is a Plymouth

[randroid]

Greenbomb,

The rear mount rubber is definitely a factor in the alignment of the drive line and could certainly be a major factor in jumping out of gear. You could theoretically adjust your linkage to adapt to it but thats not a fix so much as you're asking for more problems down the road plus fixing the original problem. Since you're going through Steele anyway you might ask them about what it would take to replace all the mounts at the same time for no reasons other than it needs to be done and you'd save on shipping.

I know of the cross-piece you mentioned but can't be of much help there other than to say I have found rubber parts stuck like you described and almost always find a washer canted at an angle and locking into the threads. With these jobs, if tapping a punch around the area where a potential washer might be found in hope of knocking it off the threads doesn't work, brute-force and awkwardness will generally prevail. Remember that you're going to replace it not repair it and it will be easier on your soul. Cutting out rubber is always a lousy job because of potential damage to threads but while you're spending money on the mounts you could buy new bolts too, and complete the job fast and guilt-free.

Since I'm not looking at pictures the above information doesn't come with a warrantee, but crawl under there and see if it doesn't apply.

-Randy

[Cpt.Fred]

My P10 used to jump out of gear sometimes, than more often,

and in the end i couldn't even get into firts gear anymore.

I changed the (totally destroyed) rear motor mounts, adjusted the linkage

and i haven't had any more issues since then.

[Don Coatney]

This is what a P-15 engine mount looks like. Not sure if your car is the same.

[meadowbrook]

I am wondering if weak rear trans mounts would cause my '50 D34 to slip off 2nd gear when I coast.

I have an R-7 BW Overdrive and besides this everything works great.

This only happens while coasting in 2nd.

Any thoughts?

[Andydodge]

I maybe wrong but aren't mopar 6 rear munts all the same, just molded rubber uppers & lowers, nothing that has to be vulcanised to metal..........you just buy the rubber parts and replace the old for new........thats what I did and the new fit fine...........Don's pics show the mount......as far as I know they are the same thru to the mid 50's.........andyd

[Greenbomb]

Well, I got up close and personal with the crossmember and I found that I have all the necessary pieces to send to Steele. Don, thanks for the pics. Your shop manual picture is a lot clearer and detailed than mine, so it's now clear how it goes together. Also, the mounts you are using are different than mine, although it appears that either set-up would work.

Thanks everyone for the input- it sounds like new motor mounts will cure several problems.

[Young Ed]

Greenbomb somewhere towards the end of the p15 model run they eliminated that lower mount. If your car only had two donuts on top of the crossmember you should be good to go.

[Greenbomb]

Ed: That's what i surmised after seeing Don's pictures and looking at what I have. I just gotta get them sent to Steele for rebuild. Thanks.

[Andydodge]

Greenbomb.......still don't understand why you don't just buy them "off the shelf" as I mentioned, I don't think that there is anything that needs to be "vulcanised" onto a metal piece..........at least thats what all the mount "biscuits" I have seen look like.........andyd

[Greenbomb]

Andy;

The mounts I have are vucanized to a "post" spacer/flatwasher unit. It's a '50 and as Ed said, they changed about then from what they had been for quite awhile. That's also what Steele lists, so I'm gonna go with that.

[Andydodge]

O/k........I have learnt something new........didn't realise that they had changed..........thanks for pointing that out...........regards......andyd

[Young Ed]

Andy;

The mounts I have are vucanized to a "post" spacer/flatwasher unit. It's a '50 and as Ed said, they changed about then from what they had been for quite awhile. That's also what Steele lists, so I'm gonna go with that.

Are you sure? As far as I know they just eliminated the lower portion and its still a seperate rubber piece from the tube. I suspect yours are just really stuck together from 60 years of holding up a flathead.

[Greenbomb]

Well, Steele says they have to have my units so they can vulcanize them. They don't list just a separate "donut" to buy. Also, one of the mounts has zero rubber on it and the other is so smashed and distorted it's impossible to tell by it what the original looked like.

[Andydodge]

I have checked my 1936-42 and 1946-54 workshop manuals and they show the same rear mount pics in both manuals and they are separate rubber cushion type mounts, they DO NOT come with any steel parts vulcanised onto them, the steel washers and plates are a separate piece that the rubber parts sit on, I have taken the mounts apart on my 1941 Plymouth and the rubber although stuck onto the steel washers was not vulcanised onto the washers. I ordered a new set of rear upper & lower mounts from Andy Bernbaum for the car, his catalog shows them as just the rubber parts, he sent just the rubber parts, I installed just the rubber parts with the cleaned and degreased metal parts and the setup is A o/k...........don't get me wrong, I suppose that somewhere, somehow, someone COULD have decided to vulcanise the metal plates & washers onto the mounts and told people that that was how they should be, but to me thats a furphy, and maybe a way to gouge more money than they should.........my 3cents Oz worth..........Andy Douglas

[sorensen_dk]

I don't want to add to any confusion, but I also know of the upper engine mounts being vulcanized to the big washer.

Back in the 70s my 38 Dodge had an engine transplant - truck engine. At that time the correct engine mounts could not be found and the best replacement parts available had the upper rubber cone vulcanized to a thick "washer". Actually the washer didn't fit the cross member but had to be machined. They had the Mopar logo and they were quite hard - my guess is it was a truck item.

Tom

[Greenbomb]

Hmmmm......The plot thickens! My manual says that the rubber should be "soft" as "hard" rubber will transfer noise and any engine roughness. Steele is the only reference I have and their catalog has several different listings by make and year. You'd think they would all be the same, but they ain't. But, it still appears to me that some would interchange well enough to work.