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Coadster32

4 speed tranny rebuild

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Time to crack my knuckles. Tomorrow I will start to tear into my 551 tranny. The last time I used it, it got stuck in reverse. It also leaks from the seals. From information I gathered, that is caused from bearing play, which I feel none. I have the manual, which tells you how to take it apart, and put it back together. Not much in what to watch out for. I have Wild Bill's articles from LAGC. (BTW-cool series of articles, but a little brief for the confidence builder.) I printed out posts from TT on the chewy looking gears, and putting the bolt heads a certain way. I remember a thread on a gear being backwards also. There's also a trick on getting it back together with the 1/4 balls (which I don't know). I guess that's pretty good but, I feel pretty blind. The tranny did free up when I pulled off the hubs, and I can get new bearings and seals locally. If it's copacetic, I'd like to take pics of doing this, and post them in this thread. I have noticed a lot of people have eagle eyes. I would have given it to charlie, but the funds for doing this are kind of low. The hitch pin came out, and from what I hear, it's a good start! :thumbs:

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You are off to a good start... I have opened up 4 or 5 trannies and the hitch pin and hub removal have always been the big problem. So bad on one I had to sawzall through the case and pin!!!

Just used the manual ....

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Chris you'll be fine. The manual is very clear and gives good instruction. Read through it first though, don't just jump in and follow along. The trick on the 1/4" detent balls is in Bill's latest article in LAGC if I remember right. Take pictures as you take it apart, that will help when you go to put it back. There's plenty of people here who have been into these things more than once and can help you with any questions.

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Well I got into it today. I must say, I felt pretty prepared, and right at home. I'll let the pics do some talking.

DSCF0082.jpgPretty stuff Huh.

DSCF0087.jpg Total runnout .002 both sides. Pretty good to me.

DSCF0085.jpg

DSCF0086.jpg

Things look about what I though they would look like.

DSCF0089.jpgAll cleaned up.

DSCF0090.jpg

DSCF0091.jpgDifferential looks OK

DSCF0092.jpg

The counterbored third gear looks really worn, just like TT explained in another thread. The input shaft gear is worn where it mates with third. The low gear is worn also. The cluster gears that these mesh with are worn a little also. If I replace just the two gears, and leave the cluster alone, it should give me sufficient engaement. (75+%). If I can get the cluster gear for resonable costs, I'll do it. The reverse gear was in backwards also. I can flip it over, and it'll be fine. I only found one ball bearing?? Perhaps that's why I was stuck in reverse. The high shift fork is 1/2 as thin as it should be. The needle bearing for the brake shaft is rusted up, and doesn't spin. I think I caught it early, because the shaft only wore down .002. (still useable). I lost a needle bearing in one of the outer axle housings also. (came apart upon cleaning). I understand how this unit works now. Really good design. I would have tried to make third a more solid design somehow. I thought the axle bearings would have been bad because of the seals leaking. From what I see, all of the seals are almost non-existant. I beleive my parts list will be:

all oil seals

one shift fork p/n 3503

Hi and intermediate gear p/n 3523

Low and reverse gear p/n 3524

brake axle needle bearing p/n 1530

axle shaft neeedle bearing p/n 1528

input drive gear p/n 3522

two ball bearings

1 case gasket p/n 3912

Cluster Gear p/n 3525

Is it true that the hi-intermediate gear is discontinuted?

Can I use gasket maker, or do I need to by the case gasket?

Feel free to whallop me on what you see. :thumbs:

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I'd like to see some closeup pics of the worn hi/lo gears and their shafts - might be able to get some made by a local gear cutter here . Need to do the same thing with my 753 when the weather breaks loose. I may also know a guy that has some of the gears and input shafts nos ...

Sarge

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Chris..... :thumbs: Fan dam tastic!!! I am just about ready to crack my 701 open for the same thing! Hoping I have the same luck you have on the drive shaft run out at least! I will have some great refrence pictures to go by! I see ya got some tight bond GLUE out of that tranny! ummm there is a lubricant that Im thinking of cant remember the name.... :whistle: I think it's Severe Gear 75-140 but I cant remember who makes it tho :whistle: Anyways great job! How much they soak you on the seals and gaskets? My center gasket was like $3.75 and the 3 big seals were $5.50 the small drive seal was like $3.50 I also priced bearings and the big one inside they want $75.00ea!!!!! I then called my local bearing warehouse doode and I can get all the seals and bearings for about 1/2 of what my local Toro dealer wants.. I purchased 2 sets of seals and center gaskets cause my 551 has same tranny as the 701. Good Idea on the dial indicator! Anyways thanks again!

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Here you go Sarge. Let me know what you can come up with. I will play coy with my local dealer, and see what he says. I think eveyone knows what he'll say, but who knows what he's got laying under his bench. Seems to me that the hardest part of this job is getting a parts supplier. That's if you can get the hitch pin and hubs off. I do have another 551 tranny, but I'd hate to pillage it. Besides, it's probably in the same condition.

DSCF0093.jpg

DSCF0094.jpg

DSCF0095-1.jpg

These pics are of the 1/R gear.

DSCF0097-1.jpg

DSCF0098-1.jpg

These pics are of the 2/3 gear. Both gears go onto the same splined shaft. The counterbor with all of the holes is actually third gear. It doesn't engage very far. So after a while when the edges get chipped out, it doesn't engages fully, and slips out. The ball detents on the shaft may hold it in untill there's a load on it. (TT stated this in another post, and I agree 100%) :thumbs:

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I went to the local dealer this morning, and this is what they told me about my parts list.

Input gear w/shaft-------------$277.88

R/1st gear----------------------$56.60

2nd/hi gear---------------------Not Avail.

Cluster Gear--------------------$299.65 new part number-7269

Case Gasket--------------------$3.76 in stock

Brake shaft needle bearing ---$19.46 new part number-83-2880

Axle shaft needel bearing------$21.90

Shift Fork------------------------$36.0

Input shaft oil seal--------------$3.55 new part number 100441

CRAP!! Mainly this is what I expected. I thought that $56 for the 1st gear was reasonable though. I bought the case gasket, and decided to pillage the other tranny. The bearings and seals I'll get from a local supplier. Who knows what I'll find in the other tranny. Both of them work, so I'll take the best parts and put them in my rebuild tranny. The other one I'll put back togehter, and it will work. I am considering replicating these rears, as they don't look very difficult to make. I see a potential need for this. Would there be any takers? :thumbs:

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Wow, those dealer/prices are on crack.

That high gear with the internal grind work would be tough unless you could find a decent /unworn example to copy from.

So, who has a like-new one?

Sarge

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