Jd450c tranny leak

[Alekanderson]

Have a 1974 450c, and losing hydraulic fluid from tranny. Appears to be coming from under engine area and draining down skid plates onto ground. Pretty good stream. Any ideas? Thanks

[rock digger]

Check the hoses that go to the oil cooler in front of radiator. I was skidding woood with mine once and one let loose what a mess.
Hope this helps. Rock Digger,

[oljoe]

If the hoses or fittings are not leaking the oil could be coming from the front seal on the transmission. I have this problem on a straight 450. It will go through about a gallon an hour. The oil was draining out of a weep hole in the bottom of the clutch housing. I pulled the engine and replaced the seals on the pump and input shaft but I still have a leak. I was going to pull the engine again this winter but never got around to it. I think maybe the pilot bearing may be bad and letting the shaft move enough to cause the leak.

Joe

[torove]

I had the same leak on my 1978 550C and got great help on this site.
You have to remove Radiator block, then Engine, then Torque converter and the big seal behind it is the culprit.
While you have it out replace any tube seals you can get to, (6 if I remember right.
The local JD dealership quoted me 6 days plus parts of about $700.
I've never opened up a crawler before, used a friends backhoe to lift engine in and out.
I counted my hours except those for scraping old gunk off outside and painting it all. It took 48 hours .
Thankyou to those who offered advice on here, I forgot to say before and this was 2 years ago.
The shuttle valve block seals were also leaking and I replaced them a bit later. If i'd known at time I would replace them at same time as the other job.

[Alekanderson]

Looks like the leak is coming from between engine and tranny, already started a dismantle. Any suggestions on engine removal? I already removed skid plate, hood, floor pans, nose, and am cleaning. I see the four bolts holding engine and tranny together, is there anything else I'm missing? I know I have to get fuel lines, oil pressure line, tach line, misc. wires. Anything else? Thanks in advance.

[Alekanderson]

Have engine out of dozer and assessed parts to repair, looks like input shaft seal is culprit. Also might have to replace input shaft, grooves look to be worn from past. Anyone have advise on pulling input shaft? Thanks

[shinnery]

Can you find a Speedy-Sleeve the right size and put it on without pulling the shaft? Just an idea if the shaft is otherwise functional.
Bryce

[Alekanderson]

Update, got a new seal installed, and no more leaks! Also fixed four more leaks in the process, now much better than before. A couple little things left and almost done!

[oljoe]

It’s great to hear that the leak is fixed. Was the seal damaged and did you need to install a sleeve on the shaft?

Joe

[Alekanderson]

Seal was in fact torn, I used a micrometer and measured, got a new seal and specs showed very close, so installed and no more leaks! Cheap fix, but many hours cleaning and dismantle.

[NIKinNZ]

Looks like the leak is coming from between engine and tranny, already started a dismantle. Any suggestions on engine removal? I already removed skid plate, hood, floor pans, nose, and am cleaning. I see the four bolts holding engine and tranny together, is there anything else I'm missing? I know I have to get fuel lines, oil pressure line, tach line, misc. wires. Anything else? Thanks in advance.

Hello Alek,

Im in the exact same position with my one just now, when it came to the ending removal, i see the 4 bolts but are there two on the back side of the engine also? i seem to have 2 partially obscured bolts going from the back to the front. Cant quite get a socket on to then as partially obscured but can just get a crow foot spanner on them? any ideas if these need to come out?

[Jim B]

Good morning,

Alekanderson may answer you, however looking at his profile it appears his last sign in here was May of 2013.

In one of your other threads/posts, I thought we had cleared up the 4 each 5/8" bolts/capscrews that had to be removed to separate the engine from the clutch housing. I have marked up and attached a drawing from the parts catalog to identify the four bolts to be removed. If these are not the ones you are asking about, posting some pictures of the ones in question would make it easier to provide you with an answer.

The only other ones I can think of might be two each 3/8 capscrews straight down into the flywheel housing right behind the engine, that hold the front of the cowl. The wheel tractors (many use similar mounting and hardware in this engine to clutch housing area) have those two (under the battery) as the wheel tractors have the battery in that area, unlike the crawlers.

[NIKinNZ]

Thanks again Jim, much appreciated, yes i got the engine out (4 bolts as stated), i now see a shaft with the throwout bearing on it Im guessing i need to pull that cover off that is held on with the 3 bolts and the seal is behind that? as listed as item 15 on this diagram I presume this will be the only/main cause of oil leaking into the bell hosing and dripping out? Thanks again.

[Jim B]

Study your manuals some more. That three bolt cover is the clutch oil pump. There is a bearing and sealing items inside it that should be replaced.

[NIKinNZ]

Thanks Jim,

Yes i have ordered the seal, yes i see they call it the Transmission Pump , or Clutch Pump, i have ordered the seals for this and im hoping this is where my transmission oil leak is coming from! i must admit, when i pulled the clutch throwout bearing, and undid the locking screw of the shaft the spring pushed the 'fingers' back and im strugging to work out how to get the spring off? i need this to access the pump to get it off (i presume) I really dont want to remove the bell housing if i can help it.