426 cat trans rebuild advice

[taggmann]

Well the cat saga continues. Thought I had the old girl fixed, see, https://www.heavyequipmentforums.com/Forum/showthread.php?t=15951 anyway, after cleaning the screen I got 2.5 hours out of it before it stopped going forward. It still goes backwards strong unlike the symptoms of the other tread, so I ordered a trans rebuild, pump and t.c. from Joseph Industries. I thought pricing was good. Anyway I'm going to rebuild it this week. Does anybody know of trouble spots or things to watch for when tearing down one of these power shuttles. I do have the parts manual but no service manual. There are shims, does anyone know the end play numbers?
Thanks; John

 

[longjrla]

taggman,

I have been reading your other threads relating to your 426 transmission problems. When you were having problems, were there air bubbles in your tranny fluid when you pulled the stick to check the level? I have a '98 426cit with the powershift transmission and have had similar problems to what you were experiencing with the intermittent use forward and backward for a few feet and then nothing. When I pulled the dip stick there were bubbles in the fluid. I was thinking a suction leak. I took it to a guy who was supposed to be a mechanic, but after a new transmission controll CPU, shift lever, fluids, filters, screen cleaning (which there were some black fibers from the clutches, etc the same problem persisted (huge waste of $). I did notice that if I ran the tranny 3-4 quarts overfull, the tranny has ran fine for 6 months now. The problem with this is I can't use 4th or 5th gear, the breather leaks all the extra oil out and I'm back to intermittent use, or it feels like it's slipping. Other than it leaking at the breather, around the level indicator view window plug, and around 4wd output shaft seal, there are no leaks, (I was tryin to find the suction leak). Can the tranny overfull raise any other havok or cause more dammage? It is a chore to take out the tranny on a dirt driveway, and with the current economic sitution, I don't have the 6K to have CAT do it anytime soon. Anyone have any input, this may help taggman and myself. Tagmann, for sihts and giggles, before you rip out the tranny, try adding a few extra quarts and see it your tranny works?

 

[taggmann]

Hey Longjrla; It's fun ain't it!?
I did notice air in my fluid to but I didn't think it was excessive. I did overfill the trans when fwd quit because it read low and I got carried away.It didn't help. Since I still had a strong rev. I figured everything.. pump, screen, pickup,, was working and with all the clutch mat. on the screen and no fwd it kinda narrows it down to fwd clutch pack.( I hope). It is anyone's guess how long the thing was run with a plugged screen starving the pump, packs, everything. New rebuild kit, pump and reman t.c. was just under 1200.00. I think that is not to bad a price.

As far as your trans. It's not the same as my trans. I have a manual 4 speed w/a fwd rev shuttle all in one case and no CPU. the shuttle has a fwd clutch pack and a separate rev clutch pack. your trans and mine are similar in that they both have hydraulic pressure operated clutch packs. It sounds like you have a pickup problem. I am not familiar with your trans. but possible screen not installed correctly or crack in housing or pickup tube. bad pump gasket?? I don't think overfilling is a long term solution.If your fluid level is high enough to contact the rotating parts. It is probably whipping air into your oil and causing internal drag in your trans (especially 4th and 5th gear). foaming, possibly more heat, blown seals, you already know. You also have the added fun of electronic controls. Again not to familiar but what does the "brain" control and know... fluid level, bad sensor, crappy elec. connections? You might want to start a new thread with your specific problem.
Thanks ; John

 

[squirtman]

Taggman or anyone can you please tell me where this screen is. I can't find it I have a 420d and it wont move. before it would just sit until it warmed up then move but it just quit. I had put in all new fuse boxes I was told something was broken in them I am trying to find it myself because that cost a fortune 75.00 an hour to trace a wiring problem which ended up in fuse box and now still wont run. I think I need a picture to point me in right direction.

 

[longjrla]

squirtman, welcome to the forum.
I don't have my manual handy to send a picture. I believe that most Cat tranny's have the screen located in the same place. There is an oval shaped plate with two bolts (roughly 2.5" diameter) located on the bottom of the tranny sump (lowest part of the transmission), directly below the torque converter housing on the bottom of the tranny. Take the plate off after draining, there should be an "o" ring, metal retaining ring, and the screen (long screen tube approx 3" long) behind the plate (at the bottom of the pump suction tube). I'm assuming that the fluid level has been checked when you were trying to move the machine, were there any air bubbles in the fluid on the dipstick? Do you have direct drive or powershift?

Taggman, any updates on the tranny rebuild?

 

[taggmann]

hi Fellas; Ditto on that sump location, I can add mine is on the passenger side and has a drain plug in the middle of the plate longjrla described.
Tore the thing down found a broken thrust washer( fiber) on the clutch pack shaft. could have been initial problem so hold up is ordering the washer. it left me thinking I just spent 1200 beans for a 4 dollar washer. Imagine my relief when i found the clutches are SPENT. I think most of the problem is heat probably normal wear n tear but could have been accelerated by starving oil through a progressively plugging screen. I also found the shift boot was ripped and letting any kind of crap in that would of course go to the screen. My advice squirtman; clean the screen, run it a little clean it again and again. new filter, run it. keep your fingers crossed and brace for a trans rebuild. got my parts from josephindustries not an endorsement just where I got mine. The thing is, what is plugging the screen is supposed to be in your clutches. Good Luck; John

 

[longjrla]

taggmann, did joseph send you a parts breakdown placement for the shims, plates, bearings, etc. Do they use the same part #'s as Cat? The Cat SIS procedures are pretty vague (such as remove ring, remove bolt, Which one?) and the parts book groups a crap load of the part number leader lines to one spot. Keep me posted after you get her back together.

Thanks, Larry

 

[taggmann]

Hi longjrla; No i did not get any info from joseph and the trans kit did not include the thust washer, maybe it should, Not a big deal got that (actually both) from cat. It did include; Clutch packs,seal kit, small parts kit and bearing kit.
It is good to have both the SIS and parts manual. I did a lot of head scratchin' looking at the SIS but once I had the trans out it became more apparent what was what. Got a couple pressing jobs but hope to get to the "hoe" by the end of the week. Here is a link to some trans part no.'s maybe your's is among them. http://www.joseph.com/PDF/Cat HE tech flyer 2009.pdf When I get back to it I will post some pics.
Thanks; John

 

[drifter590sl]

good luck with that i mean it in the best of ways

 

[squirtman]

powershift. I guess the draining part is what I didn't want to here I was told the screen was under the seat I thought I was going crazy because I couldn't find it. Its full of fluid don't see any bubbles but my eye arn't very good. Thank you for your answer. squirtman

 

[squirtman]

sorry but I fo got to ask, I read somewhere how to find all the nuetral safty switches but can't seem to find it again does anyone know where they are on a 420 d?

 

[longjrla]

squirtman,
I don't know for a fact, but I don't think there is a "mechanical type" neutral safety switch per say located on the transmission on these machines, at least on the powershift. As far as I know everything is controlled by the Tranny CPU located above the batteries in the battery box and the forward/reverse selector on the steering column. There is a "Transmission Neutral Lock" toggle switch on the left side of the front dash, and the neutral switch button on the loader controll lever, and also on the gear shift lever if it's a shuttle shift. I can't remember if the parking brake switch located on the P-brake lever assembly switches the tranny to neutral or not, or if it just won't let you select Forward or Reverse out of Neutral if it has been engaged. But then again, I can only speak for the "C" series, I never really paid mutch attention to the D's or E's on this.
Sorry, but to be certain, someone else is going to have to help you out with that one. Have a good weekeng guys.

 

[taggmann]

Running into a minor controversy between the parts book, the SIS and the quantity of clutches and plates included in the kit. You know how when your a kid and you tear something down and in your haste ya don't keep track of exactly everything and where it goes. Well I'll be 48 in aug and I still haven't outgrown it, besides I had the parts book right? Anyway.
In regards to the clutch pack, of which there are 2, 1 fwd and 1 rev, the parts book says 12 friction disks 12 plates. The kit has 20 f-disks and 16 plates. SIS has no quantity but says start with plate ( after piston) then alternate f-disk plate and so on then install retainer and have no more than .100in. of pack play(doesn't say what to do if it's not less than .100in. and the SIS doesn't have the min pack play? Seems like it's very important not to be resting to tight. Parts book diagram shows piston then f-disk (makes no sense since the piston is alum and would spin in the bore if not protected by a plate). so I'm sure the SIS is correct, plate first, nested to piston, then friction-disk and so on. according to parts book, 6 f-disk and 6 plates, I am positive I had a plate nested to the retainer(and again the retainer would spin in its bore if not protected by a plate) so if plates are 1 and disks are 2 the pack would look like this; piston1212121212121retainer. That is 7 not 6 plates. That's the way I am going to put it together, ran out of time yesterday.
The SIS is very helpful but vague, parts book must just be wrong and I guess its cheaper to give away 8 extra friction disks than to stock more packages of correct quantity. Oh and if I'm over .100in. I'll guess I'll just add a plate, they look to be about .080.. Hopefully, I've learned to pay closer attention at tear down .....hopefully.
Thanks; John

 

[Tinkerer]

Taking a lot of photos while dismantling a transmission is an absolute must do thing. You can print them out and then have them for immediate reference. Also when dismantling all the gears, plates and snap rings from a shaft , lay every item out in the exact position they came off. Be especially careful not to tun any individual part around. I learned the hard way to do this.

 

[longjrla]

Taggman,
FYI my parts book for the "C" says.
Sequence: Piston-disk-plate-disk-plate-disk-plate-disk-plate-disk-plate-disk-plate- but then specs out different part # for "end plate" - then retaining ring. The end plate would be your 7th plate as described above. Don't know what to say other than I'm sure you don't want to take it back out again. I don't think they changed a whole hell of a lot.
Your situation sounds exactly something I'd do, other than it would be spread out over a period of six months, while having your son pick the parts up and drop them in the yard "helping you". Yea, go back and try to remember where everything goes then, even though when you were taking it apart, you say to yourself, "I'll remember". Ditto on what Tinkerer says, even though it is hard for me to discipline myself to do so.

Keep us posted

 

[Per Eriksson]

SIS parts say 6 discs and 6 plates in each pack + 1 retainer closest to the retaining ring so you are correct on the quantity but the retainer are different from the other plates

 

[taggmann]

Well my son and I put the trans together yesterday, want to stick it in today. When I pulled it apart I am positive the plate next to the retainer was a regular plate but after a week positive gets a little mushy. Before we put it together we counted the old plates (7) and disks(6). so that's what I did, start with a plate end with a plate and add a plate to come into stack up spec., I got about .050in. I'm gonna check all the old plates again to see if two may be different as to be the special plates next to the retainers, like Per Eriksson said. Unless I can detect a real significant difference I'm gonna leave the thing together and put it in. So far all the plates have looked the same to me. I figured my stack up was over .100 because of wear (8k hr) but maybe the last plate is thicker? I didn't notice if it is. Thanks for all your input! I will keep you posted. John

 

[longjrla]

taggmann, no news isn't neccesarily good news. How's it working for ya?

 

[taggmann]

http://s596.photobucket.com/albums/tt41/taggmann99/cat 426/ Hi Fellas; posted a couple of pic's. Should have done more. Anyway, my son Connor and I put the trans. in on sun 14th. We just hung it before he left for school at noon and left hookup for me to do when I got to it. Finally got to it on the following sat (20th). took about half the day. hooked up everything added oil and tried it out in the driveway. I worked both fwd and rev all the gears. Yahoo! So Mon. I roaded about a mi. to a small job(dug out salted stumps) about 2 hours, roaded back. worked good. temp stayed down, so I think I'm out of the woods? Time will tell. I like the machine, brakes have a slight chatter so next step is drain the rear and put in the correct ford/cat gear oil.
Thanks again for all your input it is incredibly helpful.
Longjrla, how are you doing with your power-shift? John

 

[longjrla]

Taggmann, glad to hear she's back up an running, in both directions. Myself, I've been too busy with snow to lay it up. She's still going, with it being a gallon overfull, so I guess it'll wait till April before I re-build. I'll probably start a new thread then so keep your eye out for it. Best of luck, Larry