[mabcim]

While my engine is out I'm going to paint my tranny and address a couple leaks. The tranny was rebuilt a couple years back (but they didn't paint it ), so I'm just cracking it open and replacing the seals & gaskets.

I torn it apart this weekend but have a question things I was hoping to get forums help/suggestions on.

One leak is the typical one at the shift selector. The outer o-ring and the 'inner' seal look ok; I was hoping they forgot to change one of them, but doesn't appear to be the case.
Looking at the inner seal it is not symmetrical, so I'm wondering if there a specific side that should go in first?

With the shafts out of the tranny, when I put them together, it almost looks like the o-ring isn't thick enough. I slid the shafts together and put in the o-ring. The round part of the shaft (which ends at the notch for the outer cable bracket) sticks out more than the o-ring. So once the cable bracket is on, there will be a space between it and the o-ring. Is that correct? Is it like that so the fluid will 'press' the o-ring against the bracket? Wondering if I should put two o-rings on there. The seal kit does have a round seal/ring that is flat on the outer edges that is the same diameter as the o-ring, so I could use that instead of a 2nd o-ring from the kit.

The other leak I have is at the back where the extension is mounted. Looks like the cause of that is hair-line cut at one of the bolts. I've attached a pic to show it. What suggestion do you have for that? I was wondering if I put some Permetex 26B on there (between it and the gasket) if that would work, or if I needed to J-B Weld it.

If you got here, thanks for reading the entire post . And thanks in advance for any info.

[mustangsteve]

I have rebuilt one once and it worked good for 4 years until I went with a 5 speed. You should never use two o rings together. Did you buy some type of rebuild kit with instructions, Have you tried to Google your questions. I would use both JB weld and the permetex.

[BMad]

The manual shift lever seal looks like a seal similar to the input shaft seal, or the yoke seal. It presses in from the outside of the transmission. It needs to be lubed prior to assembly. I'm trying to figure out where the pic is taken. I'm assuming that you are talking about the tail shaft housing. If the cracks are on the inside of the housing, you will be fine. As long as no cracks are exposed outside of the transmission. Be very careful with permasnot, if you use too much, excess material can get loose and clog passages in the tranny. As I'm thinking more about the cracks, the leak is probably running through the threads and down the bolt. If you put permatex on the threads and thread the bolt in while it is wet, you might slow, or stop the leak.

[mabcim]

Originally Posted by mustangsteve

Did you buy some type of rebuild kit with instructions

It was a gasket kit from CJ Pony. No instructions. I do have the Service Manual, but does go into this detail. And yes, I have gone the Google route.

Originally Posted by BMad

The manual shift lever seal looks like a seal similar to the input shaft seal

Yup, have that one. That is where the bigger 'tube' goes through. The o-ring goes on the 'inner' shaft; around it and within the bigger shaft/tube.

Originally Posted by BMad

I'm trying to figure out where the pic is taken.

It is looking at the back of the main case. It is the bottom bolt hole for the extension/tail shaft housing. The crack does not go alway the through. But seems to be providing a path for fluid to sneak behind the behind the gasket and work its way around the bold threads; and on to the group.

Originally Posted by BMad

Be very careful with permasnot, if you use too much, excess material can get loose and clog passages in the tranny.

Yes. Would use a very thin layer.

[mabcim]

Here is a graphic of what I'm talking about for the space near the o-ring.


The pic is one I edited from a thread on another forum. So I need to give proper credit for that: C4 <acronym title="transmission">Trans</acronym> Gear Selector Shaft/Throttle Valve Shaft Leak Solution - Ford Mustang Forums

[ponyboy289]

Hey,
I received your P/M. I've blown up and built a few c4's over the years.However I am a bit rusty at the moment on the shift lever seal, So I will do some research and get back to you on that. As far as the tailshaft leak, I've never had much luck with JB Weld,but I know guys that swear by it.

This is how I would fix it, It's the main case?Right. It is empty ? Basically what I would do, is paint the edge with a light guide coat and then sand it true(I actually use a flat thick piece of glass,this is how I do all of my sealing surfaces on Carburetors and such)with a know flat file or sanding board until the paint is gone,If you sand it pretty well and still have an area of paint that tells you where your low spot(and leak) is. If the area is very low I have heard of guys filling low spots with JB Weld,letting it dry(thoroughly) ,then sanding it flush. When that's all done I would use the permatex, use what you need, just make sure if it squishes out the sides when you tighten it that it's only going to the outside of the trans and not inside as noted that stuff will clog a valve body 1-2-3,let it fully cure before you add fluid.

[mabcim]

So my next question is about the front pump/bellhousing.
I noticed when I took it apart that the bellhousing did not mate completely to the main case. There appeared to be extra casing material preventing it from mating.
Now that I'm putting it together, I can't get it to mate completely; even after removing the material. It seems the front pump sticks out from the front of the case just a little bit. I did as the shop manual said I did tightened the pump first, then put on the bellhousing. The best I can tell, it is all together correctly, but was hoping someone knew for sure.
I'm attaching a pic.

[mustangsteve]

Did the bell housing push on all the way without using the bolts to draw it down, Same as when you installed the pump in the case. Google C4 and look at some of the images and compare.

[mabcim]

mustangsteve, good question. At first it went on too hard, so I gave the bellhousing a like sanding and then it slipped on most of the way; gave it a little help with a rubber mallet. So I would say just the finally tightening was done with bolts. The bellhousing is tight to the front pump.

I did a bunch of googling (pics and vids) before posting this. The shape of the bellhousings are a litle different. The best pic I found (but it an AOD) was in cjpony: http://www.cjponyparts.com/images/1000/TRANS26.jpg
Hard to find pics of a clean tranny.

[mabcim]

Must not have been thinking last night when I searched. I did not do it in the Images section (just regular part of google). Found some better pics, but the castings all just a little different. One of the few downsides having a 64 1/2 (harder to find some stuff).

First one looks close, but resolution is too small :-(
http://image.mustangmonthly.com/f/ho...smissions_.jpg
http://transmissions101.com/images/c4-transmission.jpg
http://www.fordification.com/tech/im...-transID01.jpg
http://www.cartechbooks.com/media/wy...SA227_1-01.jpg

[mabcim]

So I think I have convinced myself the bellhousing/front pump is ok.

The manual says the play for the input shaft is 0.008 to 0.042". I borrowed a precision measure device and I'm getting 0.055". I didn't soak the clutches (as I didn't replace them, remember the tranny was rebuilt a few years ago), but those are held in by snap rings, so that I don't see how that would impact the measurement.

I took extra care during assembly, so I know all the pieces are in there (heck there are no extra parts on the floor ). So do I trust the tranny guy knew what he was doing and put the correct stuff, and/or maybe he just eyeballed it and said 'good enough' because he's done it so many times OR do I want to think I know more? Just not sure how important the tolerance really is.

[stanginthe11s]

go to google, type in monster c4 thread, that will take you to ford muscle and on that site you have everything you need to know about a c4. hope that helps.

[mabcim]

will do. thanks.

[ponyboy289]

Hey Mabcim,
Sorry I didn't get back to your p/m. I have been away for the last couple of weeks(And I'm leaving again).Anyhow, I had hoped to pull apart a trans at some point to check the o ring question for you,but time constraints will not allow that.
I viewed your photo of the bellhousing clearance and it looks acceptable to me,Every c4 I've ever seen has had a gap. I took a feeler gauge and measured three 65-66 C4's that I have laying around(2 are very original untouched factory units and one that was rebuilt) The smallest measurement that I came up with was .115" they all had areas that were wider than this in spots. So looking at these three units it looks like it's totally acceptable to have 1/8" or more of space between the case and the bell. I would say that if the bell goes on smoothly ,and the mounting areas sit flush you should be in good shape. Hope this info helps.

[mabcim]

Ponyboy,
That helps. I totally understand about time. While I was hoping to have the tranny all done the other weekend, I still haven't gotten to the shifter shaft seal yet. And with the endplay tolerance being out of whack, I think I gonig to just get new thrust washers and delay even more. I think I might get bushings while I'm at it.
Found a place that has 5 of 10 washers, so need to do a little more digging; but they do have the ones that impact the input shaft endplay.