Fluid Drive Severity and Motor Mounts

[Noah H]

Hi guys,

 

While replacing the throw out bearing on the 49, I have found some issues that would like some expert advice on. One of the rear motor mounts is cracked and in need of replacement. While the other one is in great shape. My question is do I replace both or just the one? 
 

would one bad motor mount cause clutch chatter? 
 

my next question is the fluid drive. It leaks. Since this is a driver car and do not care if it leaks (the leak is not bad) is it very critical that I fix the leak? It could of been leaking for a while as well. I will check the level.  there is a picture attached. It is upside down. 

[nc plumber]

If you don't mind that it is leaking and that you will keep an eye on the fluid level, then no it's not critical that you fix the leak. 

I would only replace the mount that's broken.

[kencombs]

Yes, one motor mount can cause chatter.  I'd replace them both.  They're both the same age and the second one could fail soon.  So, unless you want to be back under there in a month, a few months or ?  Just do it now and be done with it for years.

 

As long as the amount it leaks doesn't make a mess you can't live with or cause it to stop working, I'd leave it until if does.

[Worden18]

Noah, do you have new motor mounts on hand?  If so, where did you get them?  Good luck with the fix!

[Noah H]

1 hour ago, kencombs said:

Yes, one motor mount can cause chatter.  I'd replace them both.  They're both the same age and the second one could fail soon.  So, unless you want to be back under there in a month, a few months or ?  Just do it now and be done with it for years.

 

As long as the amount it leaks doesn't make a mess you can't live with or cause it to stop working, I'd leave it until if does.

 

20 minutes ago, Worden18 said:

Noah, do you have new motor mounts on hand?  If so, where did you get them?  Good luck with the fix!

 Thanks,

 

Would a leaking fluid drive unit get into the clutch disc? That is what I am most afraid of. It does not seem to be any where near the clutch disc. And the disc seems dry as a bone. So I believe I should be safe. 
 

I do not have any motor mounts on hand, but most likely will be ordering from Andy Bernbaum. Or if any members have any better suggestions?

 

Thanks.

[Noah H]

Here is a pic of the mounts. This is how the car came. Am I missing something? 

 

Edited October 8, 2020 by Noah H

[Noah H]

Edited October 8, 2020 by Noah H

[Dodgeb4ya]

Does the inside of the bell housing show any signs of oil misting?

If that drip is from the FD bellows seal which it looks like that is a bad leak.

That will most the bell housing chamber and soon enough get into the clutch cover and disc.

Seen that before and had to re seal the FD to fix the clutch contamination issue.

[Noah H]

19 minutes ago, Dodgeb4ya said:

Does the inside of the bell housing show any signs of oil misting?

If that drip is from the FD bellows seal which it looks like that is a bad leak.

That will most the bell housing chamber and soon enough get into the clutch cover and disc.

Seen that before and had to re seal the FD to fix the clutch contamination issue.

 The bell housing is  dry, felt with my fingers and no signs of dipping oil

[Dodgeb4ya]

What's the big drip on the FD right behind the driven plate?

That drip in your picture is typical where the failure of the bellows and graphite seal ring show leakage.

Edited October 8, 2020 by Dodgeb4ya

[Noah H]

9 minutes ago, Dodgeb4ya said:

What's the big drip on the FD right behind the driven plate?

That drip in your picture is typical where the failure of the bellows and graphite seal ring show leakage.

That is most likely where the leak is coming from. But I felt the inside of the bell housing and it was dry as a bone. No signs of oily residue or oil mist. Does this help? 
 

thanks 

[MarcDeSoto]

The leak is most likely coming from the bellows seal, or it could be coming from the FD fill hole.  I assume you have already checked the fill hole plug for a leak.  Dodge, how big a job is it to replace the bellows seal gasket?  Do you need to send the FD to a special FD mechanic?  I think you need special Miller FD tools for this too.  

 

[Dan Hiebert]

I would encourage you to replace both of those rear motor mounts.  From the photos, one of yours was replaced in the past, and it looks like the one that failed.  That one failed in part because both weren't replaced at the same time.  That causes uneven stress on the parts and certain failure in parts that are engineered to share a load.  

 

The fluid drive in our D24 leaked just like yours for many years.  Never got into the clutch, so we never had a clutch issue, but it finally annoyed me enough to fix it.     

[Noah H]

4 minutes ago, Dan Hiebert said:

I would encourage you to replace both of those rear motor mounts.  From the photos, one of yours was replaced in the past, and it looks like the one that failed.  That one failed in part because both weren't replaced at the same time.  That causes uneven stress on the parts and certain failure in parts that are engineered to share a load.  

 

The fluid drive in our D24 leaked just like yours for many years.  Never got into the clutch, so we never had a clutch issue, but it finally annoyed me enough to fix it.     

thank you Dan, never replaced motor mounts before so hopefully it’s an easy task

 

[Noah H]

[James_Douglas]

I have seen fluid couplings start to leak when people put ATF in them. Carbon Seals and ATF do not play well together over time.

 

Drain the coupling, flush it out with any cheap hydraulic fluid around and then fill it with Mobile DTE light circulating oil ISO 32

 

If you are lucky, there is build up on the seal of crap and a good flushing and proper fluid may cause the carbon sealing ring to re-seat on the steel micro polished sealing surface that the carbon seal rides against.

 

You can get that at Granger. Go search here for my document on fluid drive fluid for details on the fluid and its properties.

 

If it leaks, the clutch disc will get wet in time and start to slip. By the way, take a sheet of white paper and soak up some of what is leaking and make sure it is in fact from the fluid coupling. All of the these engines seem to leak from the rear mains. Sometimes people see oil on the couplings and think it is leaking when it is the rear main. The stock fluid will look different than engine oil on a sheet of paper.

 

James.

[Noah H]

6 hours ago, James_Douglas said:

I have seen fluid couplings start to leak when people put ATF in them. Carbon Seals and ATF do not play well together over time.

 

Drain the coupling, flush it out with any cheap hydraulic fluid around and then fill it with Mobile DTE light circulating oil ISO 32

 

If you are lucky, there is build up on the seal of crap and a good flushing and proper fluid may cause the carbon sealing ring to re-seat on the steel micro polished sealing surface that the carbon seal rides against.

 

You can get that at Granger. Go search here for my document on fluid drive fluid for details on the fluid and its properties.

 

If it leaks, the clutch disc will get wet in time and start to slip. By the way, take a sheet of white paper and soak up some of what is leaking and make sure it is in fact from the fluid coupling. All of the these engines seem to leak from the rear mains. Sometimes people see oil on the couplings and think it is leaking when it is the rear main. The stock fluid will look different than engine oil on a sheet of paper.

 

James.

Fluid has never been changed in my 5 years of owning the car. Original owner states he has never changed the fluid either. I have been using fluid drive at stoplights more often recently. Maybe this caused the leakage. Is there a fluid I can put in there that will swell the seals? I do not understand why it is leaking now all of a sudden. 

[Dodgeb4ya]

Looking at your picture you pulled the transmission...

There is no trans input shaft into the FD coupling..the transmission input shaft supports and aligns the the clutch driven plate and disc/clutch cover. Without the transmission installed into the couplings two pilot bushings the weight is stressing the bellows and graphite seal ring most likely causing the coupling to leak.

Wood wedges carefully lightly  pushed under the clutch driven plate will support the plate and bellows/ graphite ring seal.

The copper bellows and graphite ring seals can be permanently damaged from rough handling or hanging the trans in the coupling upon removal and installation.

Be careful with FD couplings.

[Noah H]

4 hours ago, Dodgeb4ya said:

Looking at your picture you pulled the transmission...

There is no trans input shaft into the FD coupling..the transmission input shaft supports and aligns the the clutch driven plate and disc/clutch cover. Without the transmission installed into the couplings two pilot bushings the weight is stressing the bellows and graphite seal ring most likely causing the coupling to leak.

Wood wedges carefully lightly  pushed under the clutch driven plate will support the plate and bellows/ graphite ring seal.

The copper bellows and graphite ring seals can be permanently damaged from rough handling or hanging the trans in the coupling upon removal and installation.

Be careful with FD couplings.

Thank you, I never thought of this. The trans is put and am waiting for a throw out bearing. The trans came out super easy without any trouble. No forcing was applied. Do you think that the seal is leaking because the trans is out? Since the trans is out, and has been for a couple days does that mean the seal is toast? Never heard of the wooden wedges as a step in removing the trans, but now, I am a bit worried. 

thanks 

[Dodgeb4ya]

The small leak will most likely stop when you put the trans back in.

I pulled the trans out of my Chrysler and the FD showed a couple drops at the bottom of it....put it back together..never leaked again.

The wedges will help prevent the seals from weeping while the trans is out.

 

[poor454]

On 10/7/2020 at 7:47 PM, Noah H said:

I am working on my 49 plymouth special deluxe. i just ordered engine mounts for it has my freshly rebuilt engine is getting delivered this week. I did not take many pics before I took it apart. Like a dumbass i throw the bolts away cause I was just going to buy new ones. So a few  questions for people. My motor mount look just like those, do I need a lower? If so where is it located at? What size are the bolts so I can go get them. Thanks Dave

[James_Douglas]

On 10/11/2020 at 7:18 PM, Dodgeb4ya said:

Looking at your picture you pulled the transmission...

There is no trans input shaft into the FD coupling..the transmission input shaft supports and aligns the the clutch driven plate and disc/clutch cover. Without the transmission installed into the couplings two pilot bushings the weight is stressing the bellows and graphite seal ring most likely causing the coupling to leak.

Wood wedges carefully lightly  pushed under the clutch driven plate will support the plate and bellows/ graphite ring seal.

The copper bellows and graphite ring seals can be permanently damaged from rough handling or hanging the trans in the coupling upon removal and installation.

Be careful with FD couplings.

I cannot remember how many times I had said the same thing on this forum. That is one of the basic things people NEED to know before they pull a transmission on one of these cars.

I, like you no doubt, wish people would read first before they start to take things apart. I have seen a LOT of cracked carbon rings.

 

The poster who started this thread should go over to the imperial club site and read how these things work. There are ZERO rubber or other seals in a fluid coupling. The only seal is one made from a solid block of Carbon and a micro-polished steel ring that it rubs against.

 

Do what I said in my last post, do what Dodgeb4ya said about making some small wood wedges, but a slit on the end of the wedges and run a long piece of bailing wire around them to hold them in place.  Once the trans is back in, cut the wire and fish it out and rotate the coupling and take all the wood wedges out.  If you pull the trans every again, put in the wedges and pull them tight with new bailing wire.

 

************
If the carbon seal is cracked...you are screwed and will have to find a seal and someone with the tools to change it. Here in Northern California, I have a full set of the fluid coupling tools.

 

James.