Allis Chalmers HD6 Clutch Problem

[mdgibbs31085]

I’m in desperate need of some advice. I have an Allis Chalmers HD6E dozer with an Auburn Style over-center clutch. Last summer I replaced the clutch plate and the 6 links on the engaging body. I also removed the slop from the clutch lever linkages. After adjusting the clutch to 30 lbs of pressure (the manual states 25 to 30 lbs), the dozer pushed like a new machine. Just one problem…after 4 to 6 hours, I find myself having to readjust the clutch. Talk about frustrating. I’ve probably only put 30 hours on the new clutch and have adjusted it 5 times. At first I thought the adjusting ring was backing off, but that’s not the case.

Any suggestions would be much appreciated. Thank you!

 

[motrack]

sounds to me like your slipping too much when you engage the clutch. My granddad had a couple of HD6s and we dident adjust the clutch once a year...... and they saw hard use.

When we did adjust them one notch was more than enough to tighten it up.

 

[mdgibbs31085]

Here is a pic of my machine doing some backfilling.

I don't ease into the clutch for it to slip. I simply pull the clutch lever back with the distinct over-center snap.

 

[motrack]

what kind of surface did your flywheel have? Any roughness to it?

 

[mdgibbs31085]

No Roughness. The funny thing about this is that the guy I bought the machine from said he had put a new clutch in it a few years earlier and hadn't used it much. Then I use 6 months and am out of adjustment, so I figured he lied and I just put a new clutch in it. Well, now I believe he did put a new clutch in it, but he was having the same problem. I replaced the six links because they were so sloppy and thought that might be why the clutch was wearing out fast. No luck there either.

 

[motrack]

to be honest unless its the wrong lineing material being used on the disk I am out of answers.

when you pull the cover to adjust the clutch are you seeing a lot of clutch dust?

 

[mdgibbs31085]

Its a tad oily in the clutch housing, so the dust is more like sludge. I'm wondering if I need a new flywheel and rear main seal???

 

[willie59]

I used to operate two HD-6's, one with a wet clutch, one with dry clutch, don't remember if it was Auburn or not. What I do remember, that wet clutch was damn near indestructable, you could abuse the hell out of it! That dry clutch...ppfffffttttttt, even with normal operation, had to adjust it often. I did find it helped a little to tighten it a bit more than the book spec, took a good "snap" to get it to knuckle in. That helped a little, but it still seemed like if you were working it hard, even with minimal engagement slipping, had to adjust that clutch way too often.

 

[Komatsu 150]

Hey, Atco I used to run HD6s too. We had a couple with dry clutches and the last one had the wet clutch. When I had an Auburn clutch it would require much more adjustment than when we ran a Rockford clutch. I used to adjust the Auburn every week or two at the most when digging every day. The Rockford would go a couple of months, it didn't last any longer just required less adjustment. We were never able to get two full seasons out of a dry clutch so we just put a new clutch in every winter. The wet clutch WAS indestructible. I measured the plates on ours when I had the engine out and there was less than .002 wear after many years of use. Great design, I think there were 5 15" copper faced discs with oil pressure fed to the center with a huge spin on oil filter. The only flaw was no indication if you ran out of oil. The previous owner of our machine had replaced the clutch because they had cracked the pan on a rock and didn't notice they were out of oil until the clutch was toast.

 

[mdgibbs31085]

Motrak, Atco, & Komatsu, thanks for you insight. Based on what you guys have said, I shouldn't have to adjust my clutch every 4 to 6 hours...so something else is at fault???

 

[motrack]

In MY experience needing to adjust your clutch every 4 to 6 hrs is excessive.

 

[dadsdozerhd5b]

that is excessive adjustment. when you pull it apart, check for hot spots on the pressure plate or flywheel indicating a warped surface. must be slipping somewhat wearing away material or else you would not have to adjust it. check runout on the flywheel for trueness also.

 

[mdgibbs31085]

Thanks everyone for there helpful insight. Hopefully in a few weeks I'll be able to post some pictures of the tear down.

 

[JTZ]

31085 hd-6

Read the threads on your clutch problems. Hopefully, you are not engaging and disengaging the clutch at high engine speeds , or under load. That will cause the problems that you have had. I am restoring an HD-5 . Bought a new clutch disc from Minn-Parr. Four disc bronze. Looked pretty abrasive. Clutch Masters,New and Remanufactured,Waterloo,Ia. Jim Keifer. 1-800-363-9825. He can get all the parts for that clutch. He made me a full fibered clutch for the HD-5. A lot smother, and will last longer. He makes them for dairy farmers, who have been know to be hard on clutches. If you do have an oil issue. That needs to be fixed. OIL= SLIPPERY!

 

[crayton]

Those should be ceramic button clutch plates and they were avaiable I think in 4 or 6 button clutches. The 6 button ones will hold better but create a lot of heat when used frequently. When they get hot things go to heck fast. Don't think you need 30 # pull on cluch lever. Have owned HD 6 s for many years and still have one. Adjust the clutch maybe once a year on a dozer so must be something else wrong. Check throwout bearing to see it's no going bad. check pins in linkage and see if any are missing,l This will happen if clutch is old and linkage is worn or pins are not installed with heads in the right direction.ie with the heads toward the front of the rotation of the clutch so the preasure is against the head and not the cotter pins. Also use hard steel cotter pins. The other thing that could happen is you have lost the thrust bearings on the center main of the crankshaft. They are seperate pieces and held in with small brass pins and are prone to falling out. Check end play on the crankshaft by prying it back on the front and then engage clutch. Should not move much over .010 Also check the center hub and clutch for hard steel bushings where the pins go. if these were not replaced when clutch was rebuilt the pins will wear into the hub or clutch and change linkage fast. Also the bushings in the bell housing where the cross shaft pivots are supposed to be needle bearings and will fall apart and shaft will wear into the housing. Probably best to remove whole clutch and fix it right and it will work. Think you would be better off with a rockford clutch. Try "Norcan Parts" Spokane Wa. 509-466-3566. They can most likely furnish a complete rebuilt clutch or parts and they will be good. Don't think the lever pull on a ceramic clutch should be over 10-15 # . Preassure plate and flywheel will look kind of rough on ceramic clutch but I never had any problem with them. Nice looking dozer you have there.

 

[mdgibbs31085]

JTZ and Crayton thanks. Weather here in IL hasn't really allowed for a in-the-field overhaul yet. I was cleaning out waterways for a guy in late Nov. when I lost everything. As I disengaged the clutch a nice rattly-bang noise came from the clutch area. I opened the inspection plate on the clutch housing and saw that several linkage pins had came out and the entire engaging piece had spun out of its yoke. Talk about a nightmare!!! Since then, we've had snow and cold so I'm waiting for better weather.

I originally asked about clutch adjustment because that was the problem prior to Auburn Grenade going off inside the housing. Anyway, I see a lot of new parts going into this old Allis.

On a side note, I puchased my parts from General Gear & Machine in Boise, Idaho and they were very knowledgeable and polite. I would recomend their service to anyone.

Anyone know where I could find some tracks??? Or, what other Allis crawlers used the same tracks?? I know the number of links would be different, but I could piece something together.

 

[crayton]

MD, Tracks are the same pitch on the HD-5 but will be shorter. One more roller in the frame. Rollers are the same too and sprockets. I put a new set of BerCo rails on and have had good luck. Also take note of the square blocks that hold rollers on to the frame. They are thicker on one side than the other. If the rollers are worn down some you can reverse the blocks and lower the rollers and it will give you a much smother ride. Have also put1/2 in plate under them to set rollers down. Be careful having those rollers rebuilt as they shrink when welded on and the bearing boss's dont fit and will fail. Should be machined out to size but I haven't found anybody that can do it right. Give that Norcan outfit a call, they are really good. Also if you work on the rollers make sure they are reinstalled square to the frame as they can twist a little and that will make your track run to one side. I notice you don't have rock guards so you will not have to remove the bolts that hold the reciever plates in place inside the track frame. I used to remove rock guards and then reinstall bolts before removing the rollers. Had a HD_5 that came from factory with rollers installed crooked and fought it for a coupla years before we discovered that. If you could put a tilt cylinder on one corner of that blade you would thank yourself every time you run it. Still one of the best small cats ever built for it's time.

 

[mdgibbs31085]

Thought I'd add some more pics of my HD6 before the breakdown. Put this 6 ft culvert in for a guy. Here are some before and after pics.

 

[Komatsu 150]

I would have to say that the later serial number HD6s had different track from the 5 and definitely different sprockets, all from working with a bad memory understand. The 6 changed a lot over the years. The last even had power steering clutches!

 

[mdgibbs31085]

I finally got my machine tore down. I will post some pictures of the damage later.