clutch work, new pressure plate fingers or new pp assembly?

[charlz]

My Kubtoa B7100d has been giving me clutch troubles lately. It does not fully dis-engage when pushing in the pedal. At real low engine speed you could shift gears but not at 'normal' engine RPM's. Clutch adjustments did not help much/for long. I suspected the release bearing based on the rumbling sound. Tractor works and sounds fine while in gear.

So I split the tractor, release bearing appears OK (will replace anyway), but the pressure plate fingers are worn pretty good.

about $12 per finger, 3 fingers for total of $36
$85 for new pressure plate assembly

I do not have a clutch alignment tool so am a little leery of taking the clutch completely apart (pressure plate fingers look like you can change them without disassembling the clutch). Anybody got any 'socket in a socket' clutch alignment tool short cuts here?

The clutch disk thickness appears OK about 1/8th inch on the pads. I have a repair manual on the way so hopefully will be able better judge tolerances after it arrives.

So should I just try to change the fingers or go the 'whole nine yards' with a new pressure plate assembly?

Thanks,

Charles

 

[cp1969]

While you're in that deep, I would recommend that you rebuild the clutch completely--new (or rebuilt) pressure plate, clutch disk, throwout bearing, and pilot bearing.

FWIW, a bad pilot bearing can cause the problem you describe.

As far as alignment goes, I have a tool that has various size ends to plug in the pilot bearing and has a tapered cone which slides to center the clutch disk. They're common. You can probably get one at Sears.

 

[bx23barry]

While you're in that deep, I would recommend that you rebuild the clutch completely--new (or rebuilt) pressure plate, clutch disk, throwout bearing, and pilot bearing.

FWIW, a bad pilot bearing can cause the problem you describe.

As far as alignment goes, I have a tool that has various size ends to plug in the pilot bearing and has a tapered cone which slides to center the clutch disk. They're common. You can probably get one at Sears.

Yes X2

 

[dfkrug]

I have done a number of clutches over the years, but I have never
heard of separately replaceable pressure plate fingers. How does that
work?

Since the parts cost is a small part of this kind of job, I replace them all,
plus re-surface the flywheel. I don't change a flywheel unless the
starter teeth are damaged.

 

[KJM]

I just did the same job on my (new to me) B7100D with 3700 hours on the clock. Had exactly the same symptoms as you!

My b7100 has a FEL and backhoe, both sub-frame mounted. Splitting the tractor involved using an angle grinder to cut parts of the subframe - it kind of cradled the bell housing! So cut and then weld to re-assemble. Building a subframe around a small tractor seems like a dumb idea to me ;-)

The pressure plate and the driven plate looked fine when I pulled it apart on first inspection, but the splines on the driven plate were WORN big time. The spigot/pilot bearing on these tractors is a bush - with a teflon lining. The pilot bearing was non-existant on my machine! The thing had long since died, the OD of the new bearing is 17mm, the hole in the back of the crank was 19.4mm :-( One of those moments when your stomach does the disappearing bit for a while...

I ended up getting a standard 20mmx14mm sintered bush and reamed the back of the crank. The motor spins at 2800rpm max, so I felt slightly happy doing the reaming by hand - I didn't want to pull the engine down too!

Now it is all back together, it runs beautifully. Alignment wasn't a biggie - the only significant problem was that the clutch alignment tool I have was too big! I think every alignment tool you'll find will be too big. The little cones that they have are too big to go through the pressure plate! I ended up using a piece of wooden dowel, with the end turned down to 14mm to fit. Like everyone else has suggested - go the whole hog and replace the bits. My pressure plate looked OK and measured up just fine, but for the money it just wasn't worth skimping.

Whole job wasn't hard/difficult or time consuming. Biggest problem was the pilot bearing and sorting out a logical solution to the gaping cavern in the back of the crank....

Cheers
/Kevin

 

[charlz]

I just did the same job on my (new to me) B7100D with 3700 hours on the clock. Had exactly the same symptoms as you!

My b7100 has a FEL and backhoe, both sub-frame mounted. Splitting the tractor involved using an angle grinder to cut parts of the subframe - it kind of cradled the bell housing! So cut and then weld to re-assemble. Building a subframe around a small tractor seems like a dumb idea to me ;-)

.....

Cheers
/Kevin

Mine has about 3850 hours so maybe that's about how long a clutch lasts? Dunno if it has ever been replaced before.

I inspected things again last night and I think the clutch disk is worn more than I originally thought so it looks like I will end up doing a complete rebuild.

Mine has the backhoe and FEL as well. The subframe is a serious pain, probably doubles how much time it takes to split the tractor. I already had the backhoe off but did not want to take the FEL off as that looks like an all day job by itself. I blocked up the rear of the subframe and then took out the bolts to the rear end and the bell housing, it now supports the front end of the tractor (not sure if this is the best idea but it works). I then supported the rear half by a jack through the X of the subframe and carefully slid it back a bit at a time. Going back together is going to be much more interesting, I might need to rent an engine hoist or something to hold the rear part of the tractor for those fine adjustments.

Keeping my fingers crossed on the pilot bushing!

Thanks for all the input!

Charles

 

[KJM]

I supported the FEL on a ladder and put the backhoe arm out. So I could move the front of the tractor. This was a mistake - the driven plate was a bit stuck on the gearbox input shaft splines - so it dragged the shaft forward and there wasn't enough clearance to get in there and grab a hold till I "wiggled" everything a bit!

The bolts holding the flywheel were a character building experience to remove - an air impact tool was ultimately used (which made it trivial). I was a bit leery about using a screwdriver to lock the flywheel by the ring gear - the aluminium castings didn't look like they'd cope with the force I was having to use to break the bolts...

If it was a simple split-n-fix, I'd rate the job as no more than 4 hours. Not hard at all - alignment just requires *grunt* !

Cheers
/Kevin

 

[PineRidge]

I have done a number of clutches over the years, but I have never
heard of separately replaceable pressure plate fingers. How does that
work?

Since the parts cost is a small part of this kind of job, I replace them all,
plus re-surface the flywheel. I don't change a flywheel unless the
starter teeth are damaged.

My last rig suddenly started grinding the gears whenever I would make a shift. I pulled the inspection plate off the side of the bell housing and each finger was held in place with a pin secured by a cotter pin. I rotated the engine checking each finger and low-and-behold one pin was half out of the pressure plate. I got a long socket-wrench extension and a hammer and was lucky enough to work the pin back in place. Then I got a magnet and fished the cotter pin out of the bottom of the bell housing. It was never bent over. And with the help of a set of long needle-nosed set of pliers and some rather loud cussing I was able to get the cotter-pin where it was supposed to go and bent it over so it didn't come out a second time.

Did I say that I'm a happy hydro man now? Heck with clutches, pressure plates, and throw-out bearings......

 

[Dargo]

Did I say that I'm a happy hydro man now? Heck with clutches, pressure plates, and throw-out bearings......

Many years ago I had this penchant for drag racing. With 2 guys helping me, I could change the clutch, pressure plate and throw out bearing on a '70 Camaro in just under an hour and a half from start to backing out of the garage. Although I've never done a tractor, I'd bet I've done 50 or 60 cars and trucks. Do you know what the worst feeling in the world is when doing a clutch job? It's when the job is one of the real killer jobs that take forever and, when you are finally finished and sit in the seat to back her out of the garage and you look over in the passenger seat and see the box with the throw out bearing sitting there. That sucks!! Yeah, you know how I know that! For just a split second you think, "will it work without a throw out bearing...?"

As others have mentioned, I've never heard of changing the tines in a pressure plate. Most I've ever seen were riveted in place and I certainly wouldn't want to screw with them. Heck, one other funny thing; I was putting a clutch in a '70 Chevelle with a 454 and had the clutch bolted up to the flywheel with the alignment tool still in place. I got distracted by something and, for some reason, decided to fire up the ole hot rod to hear her run before I put the tranny and drive shaft back in. It started right up, sounded good and everything. That is when I decided to rap the engine up really hard and the metal alignment tool (an old pilot shaft from a bad tranny) dropped out in my parent's garage floor! That thing ran across the floor and went up about 7' of a drywall wall (ripping it apart on the way up). It then dropped back down to the floor and shot out the open garage door, across the street and ran off into the woods. I never found it!

Good luck, and replace the whole assembly!

 

[kenmac]

I agree with all here . For $ 50.00 difference. I wouldn't want to split the tractor again fror $50.00 . Replace it all while your there, That's cheeeeep insurance.