Sometimes even the books fall short

[Jeff Balazs]

Here is something I have run into recently while trying to source a replacement 10" clutch for my B-3-C fluid drive 4 speed. Apparently this clutch is unique to this particular model and uses a larger 1 3/8" splined center hub. There is a different part number for this in the parts manual but there is no description about how it is different from say an earlier 3 speed fluid drive. From what I have been able to garner the earlier fluid drive trucks may have used a 1 1/4" splined center hub. Again I can find nothing in writing to actually verify this.

So far the people I have talked with about this seem unaware that the 1 3/8" splined center was used on some 10" diameter clutch's.

Can anyone here shed some light on this?

 

Thanks, Jeff

[Dodgeb4ya]

I would pull the disc and check it before believing what the parts books are telling you.

1-1/2 ton and up standard spur gear 4 speeds are 1-3/8" with an 11" disc.

I cannot imagine just the B-3-C trucks using a unique FD input shaft  4 speed syncro trans.

[Jeff Balazs]

Bob;

The alignment tool that I got and used came from Tennesee Clutch. I had this rebuilt a couple of years back. It is a 1 3/8" dia. 10 spline pattern tool.

Since I used it and and it worked perfectly I am pretty certain the clutch that is in my truck has a hub that matches it. I just purchased a rebuilt fluid drive clutch and it came with the smaller 1 1/4" pattern hub. I certainly wasn't expecting this difference. I think that this difference came about when the factory started fitting the later 4 speed synchro transmissions? I was hoping that maybe someone here had one or more of these sitting around that they could measure. Based on what I could see in the parts manual it looks as if the fluid drive trucks all share the same pressure plate assembly.......but it looks like there were at least two variants of the friction disc?

 

Jeff

[Dodgeb4ya]

The FD coupling in the trucks is the same unit used in the 1946-50 Chrysler Straight eight 10" cars. Using the std 1-1/4" input shaft with both oilite shaft bushings.

The only FD 4 speed B3D trans I have I think is a 1-1/4 typical shaft.

I'll check it out later in the week.

If you have a 1-3/8" 10 spline input shaft I would think the front bearing retainer would have a larger diameter and possibly then reqire  a larger throw out bearing sleeve also.

[Jeff Balazs]

The FD coupling in the trucks is the same unit used in the 1946-50 Chrysler Straight eight 10" cars. Using the std 1-1/4" input shaft with both oilite shaft bushings.

The only FD 4 speed B3D trans I have I think is a 1-1/4 typical shaft.

I'll check it out later in the week.

If you have a 1-3/8" 10 spline input shaft I would think the front bearing retainer would have a larger diameter and possibly then reqire  a larger throw out bearing sleeve also.

Bob;

It is possible that the throw out bearing sleeve is different as well. Dunno?  I haven't got that far. I wasn't really expecting any of this. I suppose I just assumed that all the fluid drive trucks used the same clutch.........

I am going to try and take a look at some of this by pulling the inspection pan this weekend. The truck is in daily use and I don't have a rack.....so we will see.

It would be great to get to the bottom of this little mystery........I am sure there will be others that would like to be certain about all this

 

Also it should be noted that changing a clutch on one of these fluid drive 4 speed equipped trucks is quite a bit more involved than it is on a standard non FD truck. Because the greater length of the FD bell housing and 4 speed transmission combo it is necessary to remove the gas tank to gain access to the bolt in cross member. This has to be unbolted and moved back several inches to have enough room to remove the transmission. There is also an issue accessing the transmission top cover which needs to be removed if you are not up on a rack. I modified my floor board.....but the factory should have done this in the first place. Owning a FD truck is "interesting".

 

Jeff

Edited April 7, 2016 by Jeff Balazs

[wallytoo]

i certainly don't know.  dad's b-3-c is fluid drive, but only 3-speed.  i don't believe we ever changed the clutch on it back when it was in use, and it has been unused in the garage since 1987.

[Jeff Balazs]

Hopefully we will find some answers on this subject. It is very hard to tell much from the parts book as there is little to no engineering data or specs in it.

There are some different part numbers called out for the different applications of the FD clutch in these trucks. But all it is ...is a clue that something different is going on for one application versus another. There are even some changes in parts numbers between clutch components used with the early spur type 4 speeds and the later helical 4 speeds. But data like this is useless without a description or an explanation. And as time goes by the people who might know the differences are becoming harder to find.

 

Jeff

[desoto1939]

Jeff I sent you a PM. Have a Borg Warner Clutch catalog.  I see 1 3/8 clutches. Send me you hom e email can copy the data for you.  Or get the whole catalog on cd for 15 + 3 for shipping.

 

 

Rich Hartung

Desoto1939@aol.com

[Jeff Balazs]

I found a fluid drive 4 speed listed on Ebay and have asked the seller to measure the splined section of the input shaft.

I believe it is the later 4 speed version. May be a clue here if I get an answer back.

 

Jeff

[Jeff Balazs]

Foiled by of all things ........ rain. It almost never rains here. Almost being the key word. I just about finished getting ready to drop the inspection pan for a look-see out in my driveway when the rain started coming down. Drats! Was hoping to get enough of a view to perhaps see what was going on here. My tiny garage is just too small for this sort of work.

 

Jeff

[Jeff Balazs]

So the plot thickens a bit. The ebay seller I contacted has verified the splined input shaft diameter as 1 3/8". But unfortunately while he has the transmission, bell housing and fluid drive the clutch itself has gone missing. What he has all came from a 1953 B-4-C parts truck he has broken apart and is selling off.

At this point I don't know how long this clutch variant was produced or how many different models may have used it.....but I do know it is genuine.

 

Jeff

I think the part no. for this clutch disc is 1194 269 which seems to be a unique number associated with the 4 speed fluid drive trucks.

Edited April 11, 2016 by Jeff Balazs

[Jeff Balazs]

I may have located a NOS clutch disc with this part number. It will be interesting to see if it actually has a 1 3/8" hub.

One thing is clear this clutch is a bit of a rare bird as far as the spares situation goes. I have not been able to ascertain when it was in production and specifically what years and models used it. I don't even know if all the FD 4 speeds used it or if it was a late production item.

 

Jeff

[Merle Coggins]

When I did the clutch on mine I sent out the pressure plate and clutch disc to be reconditioned. I didn't try to source a new one, so I have no reference on shaft size. I never had to measure it. Of course I have the earlier version 4 speed (spur gear) with FD.

 

Merle

[Jeff Balazs]

Merle;

I know....I did the same thing when I had it rebuilt a couple of years back. To be honest I figured all of these were the same???

Perhaps someone out there has some of these out where they can take measurements? Pinning this downt may be helpful to someone in the future.

 

I want a spare for a couple of reasons. My truck is in daily use and I would prefer to be able to deal with this sort of repair in one shot rather than having to tear it apart then wait on a reline job. Also since this is and will always be my only vehicle having a complete set of spares for all the common wear items just makes sense. My goal from the start has always been to build a truck that I could keep on the road with as little outside assistance as possible. Having a comprehensive set of quality spares is a big part of this program. I do know that most folks who own one of these trucks don't look at this the same way I do. That is OK.....but if it is all you got and you want it to be in top form you will need to take another view.

 

Jeff

[JBNeal]

From the literature I have read, one of the advantages of having the FD was that it would reduce wear on the clutch. If this is true, how long would the clutch last? I ask because having a spare on standby for something that may take years or even decades to wear out, that spare may get lost or degrade to the point of ineffectiveness...for example, I bought several tires back in 2002 that were on sale, yet they are still in storage because I have not needed them until recently...now that they are over 10 years old, I have been told by one tire guy that it is illegal for him to mount them (complete hooey from a dude with a case of the-don't-want-to's), so they are practically useless (for now). My point being that spare clutch may sit in a safe place for years, then when ya get around to needing it, it does not work out how ya want. IMO if ya have a fresh working clutch, I would be more worried about an oil leak saturating the disc before the clutch disc alone became a problem, and on a fresh rebuild that is being maintained, problems in that area probably won't crop up for another year of the red bird

[Jeff Balazs]

From the literature I have read, one of the advantages of having the FD was that it would reduce wear on the clutch. If this is true, how long would the clutch last? I ask because having a spare on standby for something that may take years or even decades to wear out, that spare may get lost or degrade to the point of ineffectiveness...for example, I bought several tires back in 2002 that were on sale, yet they are still in storage because I have not needed them until recently...now that they are over 10 years old, I have been told by one tire guy that it is illegal for him to mount them (complete hooey from a dude with a case of the-don't-want-to's), so they are practically useless (for now). My point being that spare clutch may sit in a safe place for years, then when ya get around to needing it, it does not work out how ya want. IMO if ya have a fresh working clutch, I would be more worried about an oil leak saturating the disc before the clutch disc alone became a problem, and on a fresh rebuild that is being maintained, problems in that area probably won't crop up for another year of the red bird

You are probably right...except that mine already has premature wear. I swapped the rear axle out on this truck and it is a bit too high. So when you combine the higher gearing and the frantic traffic here you get something that would not have happened with the original gearing.   Of course the truck would have been next to useless with that gearing but that is another story. I will say right now that I should have been a bit more conservative with my ratio choice of 3.55......3.73 would have been closer to ideal. That is of course with a good dose of hindsight and about 9 months of using it daily. So now I am into the process of ironing things like this out.

As far as what actual clutch life is going to be it is hard to say. This is a fairly heavy truck at a shade over 4000# and I have been pushing it to try to keep up with traffic. There are also a lot of steep hills and grades here.  Once i get this clutch changed I think my next move will be to get a set of smaller OD tires to reduce the load on it. Right now it is just loafing along at 65mph so there is clearly room for some fine tuning of this.

 

Jeff

[Don Coatney]

Jeff, Not sure what your driving habits are but it seems to me that the fluid drive should absorb most all clutch friction wear irrelevant of differential gear ratio. Are you slipping the clutch on every start from a dead stop? If so why? As JBneal said a fluid drive clutch should last a lifetime. 

[wallytoo]

agree.  should be able to pop the clutch pedal without feathering it at all.  come to a stop, shift to first, hold brakes and let clutch out quickly.  hit accelerator when ready to move.  rinse and repeat.

[Jeff Balazs]

Jeff, Not sure what your driving habits are but it seems to me that the fluid drive should absorb most all clutch friction wear irrelevant of differential gear ratio. Are you slipping the clutch on every start from a dead stop? If so why? As JBneal said a fluid drive clutch should last a lifetime. 

I wish I felt like this clutch would last a long time. My gut and a lifetime of driving is telling me another story.

Taking off in gear without slipping the clutch is doable but it makes for a somewhat sluggish start. I can get away with this sometimes but in other driving situations it feels like an invitation to getting rear ended. Even with the higher ratio rear axle 1st gear is much too low to be of any use 99.9% of the time so second gear starts are the norm. And a bit of clutch slipping in second gives the quickest result the way the truck is set up at the moment. I am hoping smaller OD tires will help alleviate this.

No matter what any of you may think ....... pokey take offs' in this traffic is the best way to get involved in an accident.

 

As far as how wise it is to have a spare clutch on hand goes it is a matter of what your point of view is. I would rather have it on hand. If it sits on a shelf for 50 years and rots ...... so be it. I can live with that. And I will feel better just knowing I have it if I do need it. We all have differing viewpoints on stuff like this......and obviously I don't trust this clutch at the moment.

 

Whether or not I have a spare clutch should not be the main focus of this discussion. I started the thread because it is not clear to me and others what the correct replacement clutch is for this variant of fluid drive truck. When I find out I will report it here. Maybe this information will be of use to someone who may be trying to put one of these back together.

 

Jeff

[JBNeal]

In my collection of yard art, I have a '52 near complete FD rolling chassis with title that may get a '51 near complete donor body, and have taken note of the various experiences & opinions of other FD drivers.  With your rear axle ratio change, I am kinda wondering if the FD coupling is slipping from excess loading.  Changing your tire size may reduce this loading, but it might not be enough as the fluid inside the coupling can only shear so much before slipping...if your dead load is in excess of that maximum shear force in the coupling, then the clutch may be mating up as it should but the coupling continues to slip.  I bring this up as I have seen hydrostatic transmissions on small tractors really heat up and start to slip from overloading by operators in the springtime, usually when mowing thick tall weeds on property that the tractor can easily mow when the vegetation is shorter (less load).  Others may have made the swap to the 3.55 and have had good results with their standard clutch setup, but what may be lurking over the horizon for them is an inevitable nagging clutch slippage that will have to be addressed.  The FD appears to be amplifying this issue, as it is designed to slip to protect the clutch and other driveline components.

 

As far as the accuracy of the factory parts manual is concerned, I generally take that information with a grain of salt, as I have seen errors in catalogs from Mopar, GM, CaseIH / IHC, John Deere, Subaru...they are small errors, but when ordering parts, an error is an error if things don't line up or fit.  At 2 previous OEMs I worked, the parts guys would rely on info from the engineering dept, and engineering mgmt. would make the business decision to put the least amount of resources as possible into maintaining legacy equipment, as they would surmise that any problems in this area would either work themselves out as equipment would disappear through attrition and/or there would not be enough parts sales to justify the engineering time needed to straighten this out.  There was one repair kit we sold for $20 that had the wrong hardware called out; to change the documentation would cost engineering about $200 in ECNs and dispositions, the parts involved cost $5, and sales were weak annually but steady, so mgmt. assumed that service depts. in the field were fixing the problem out of their pocket and opted to allocate resources elsewhere (even though I had marked up all of the drawings / parts lists involved for revisions, it still needed to pass through half dozen other ppl for proper documentation).  And the running change in engineering was the biggest culprit of errors in parts catalog, with these Pilot House trucks seeming to have them when referencing the S/N application notes for parts disposition.  At any rate, if there are more than one FD clutch applications out there, I would not be surprised...I have found on two of these trucks that the parts on truck (one being an entire engine) don't match up to what is in the catalog...one truck has a Chevy air cleaner on it, ya may have a clutch disc from a Studebaker in there for all we know
 

[Jeff Balazs]

In my collection of yard art, I have a '52 near complete FD rolling chassis with title that may get a '51 near complete donor body, and have taken note of the various experiences & opinions of other FD drivers.  With your rear axle ratio change, I am kinda wondering if the FD coupling is slipping from excess loading.  Changing your tire size may reduce this loading, but it might not be enough as the fluid inside the coupling can only shear so much before slipping...if your dead load is in excess of that maximum shear force in the coupling, then the clutch may be mating up as it should but the coupling continues to slip.  I bring this up as I have seen hydrostatic transmissions on small tractors really heat up and start to slip from overloading by operators in the springtime, usually when mowing thick tall weeds on property that the tractor can easily mow when the vegetation is shorter (less load).  Others may have made the swap to the 3.55 and have had good results with their standard clutch setup, but what may be lurking over the horizon for them is an inevitable nagging clutch slippage that will have to be addressed.  The FD appears to be amplifying this issue, as it is designed to slip to protect the clutch and other driveline components.

 

As far as the accuracy of the factory parts manual is concerned, I generally take that information with a grain of salt, as I have seen errors in catalogs from Mopar, GM, CaseIH / IHC, John Deere, Subaru...they are small errors, but when ordering parts, an error is an error if things don't line up or fit.  At 2 previous OEMs I worked, the parts guys would rely on info from the engineering dept, and engineering mgmt. would make the business decision to put the least amount of resources as possible into maintaining legacy equipment, as they would surmise that any problems in this area would either work themselves out as equipment would disappear through attrition and/or there would not be enough parts sales to justify the engineering time needed to straighten this out.  There was one repair kit we sold for $20 that had the wrong hardware called out; to change the documentation would cost engineering about $200 in ECNs and dispositions, the parts involved cost $5, and sales were weak annually but steady, so mgmt. assumed that service depts. in the field were fixing the problem out of their pocket and opted to allocate resources elsewhere (even though I had marked up all of the drawings / parts lists involved for revisions, it still needed to pass through half dozen other ppl for proper documentation).  And the running change in engineering was the biggest culprit of errors in parts catalog, with these Pilot House trucks seeming to have them when referencing the S/N application notes for parts disposition.  At any rate, if there are more than one FD clutch applications out there, I would not be surprised...I have found on two of these trucks that the parts on truck (one being an entire engine) don't match up to what is in the catalog...one truck has a Chevy air cleaner on it, ya may have a clutch disc from a Studebaker in there for all we know

 

You make some very good points. I am not sure if the FD is actually causing any problem. I have not experienced any slippage yet. What I have noticed is a change in the point that the clutch engages. It has been noticeable and yes I have adjusted the pedal linkage. It just feels to me like it is wearing but I suppose it could be something else. Not sure what and with the FD thrown into the equation it has me thinking that it is accelerated wear.

 

As far as a replacement goes it looks like I actually have one located......and it is 10" dia. with the 1 3/8" hub and a genuine Mopar item with a part number that match's what I found in the parts book. I was told by a few well known suppliers that it did not exist or that they have never seen or heard of this one. With no engineering data in the parts book and nothing in the repair manual it needs to be noted somewhere.......and not just be a wild guess on my part.

 

Since I began the journey of bringing my truck back to life I have stumbled across several items which make these fluid drive trucks a bit unique. And by stumbled I mean to say that there is literally nothing in the books and manuals to prepare one for some of these little "differences". This clutch disc is just the latest unique item to surface. Some of the other items are just as significant. The prime example and one that probably crosses over to the cars equipped with fluid drives is the existence of a special rear main bearing that was developed to to handle the load generated by the extra rotating mass of the fluid coupling. There is nothing in the manuals about this......but it does exist. I managed to locate a NOS one made by Federal Mogul. I am fairly certain that it was developed as an aftermarket fix for a standard bearing wear related issue. This is just another example of a specific FD part that exists but has sort of been lost in the mists of time.

 

Jeff

Edited April 14, 2016 by Jeff Balazs