[deserttoolman]

I am having a persistent problem with my 1967 Dearborn 3-speed tranny, involving a rattling noise and leak. The rattle is apparent when in neutral and clutch engaged. The leak is slow, but appears to be coming from the front of the tranny.

The tranny was professionally rebuilt, installed, and experienced these problems. Less than 5 miles on the tranny when the problems started. When I took it back to the rebuilder, he informed me that there was damage to the counter shaft causing the rattle, and the o-ring seal on the countershaft was twisted/damaged causing the leak. He rebuilt with new parts, at a considerable cost I might add, and I reinstalled the tranny. For awhile, there was no leak or noise, but now after about 200 miles on the tranny it is doing the same thing.

I am worried that the same problem exists, but I cannot understand why it would be. I am going to contact the rebuilder again, but my concern is that there is something unique about rebuilding these tranny's that he may not be aware of. He is a general mechanic who appears to be very knowledgeable, but I just don't know.

Any pointers or inside knowledge out there?

[Jack Gifford]

I don't recall anything unique about those transmissions- pretty straightforward. I, also, would first suspect something related to the countershaft/cluster-gear, given the rattle in neutral. For whatever it's worth- many transmissions become junk due to the condition of the countershaft-bore in the front face, since the countershaft needs to be a very precise fit in the case. How about doing some inspection yourself? Just pull the cover off and feel for radial play in the cluster gear- shouldn't be able to feel any, nor see any movement at all of the ends of the countershaft. Excess endplay of the cluster could also cause a rattle- a Ford shop manual would have endplay specs- I'm guessing it's .010" or less. The manual also spells out disassembly/reassembly procedures, if you want to go through it yourself- it ain't rocket science, as they say! The only special tool I can think of that's needed is a dummy-countershaft, which isn't difficult to come up with. To me, the hardest part is getting all the pieces absolutely clean, to inspect them. If it's your first time, do the disassembly on a tray that will catch any needle bearings (or other tiny parts) as they fall out (and they WILL fall out). Losing just one of the needles in the wolly-boogers under the workbench will prevent putting the sucker back together- ask me how I know!

[Jack Gifford]

I know how to spell "woolly booger"- I just have trouble typing it!

[stevep]

Do I understand this situation properly??

The trans was rebuilt, and installed it, put 5 miles on it and it developed a problem, you took it back to him, he opened it up, found more damage and recharged you?

[69Customs]

Put 5 miles on it, then problem, then he fixed it again and after only 200 miles problem back? Did he give you a warranty on his work?
The 3 speed toploader is one of the simplest transmissions to work on. Pontiac only put them in the high torque cars cause the Saginaw 3 speed couldn't handle the torque for the warranty.
If he rebuilt this what parts did he replace? Bearings? Synco's? Countershaft? Seals?
A professional will stand behind his work!
If it leaks oil out the front it comes thru the front nose seal which if replaced has been damaged by too much play in the input shaft? Was the front bearing replaced.
Also note that in order to fit the Dearborn linkage under the Pontiac tunnel the trans had to be tilted at a 7 degree angle which makes overfilling the oil easy since the fill plug is on the pass side. Could it be as simple as overfilled trans?

[deserttoolman]

I really appreciate everyone's valuable input, it is very helpful. I'll try to reply to all the questions.

The trans was rebuilt, and many parts were replaced.
> Bearings, bushings & seals
> Sychros
> Counter shaft
> Idler gear
> Input shaft

The guy who built it will stand behind his work, but I want to know what the problem is to ensure I only have to go through this one more time. I will be pulling the trans this week, and will do the inspections suggested myself. This is most helpful.

I did fill the trans prior to installation, so it could be excess fluid for the leak, but if that was the case where would it leak from? I will check that.

Regarding the issue of input shaft play, yes the bearing was replaced. But in order to eliminate that as a possible problem, what should I look for in terms of input shaft play?

Thanks again to all for your help. It sure is good to have someplace to go when I have reached the limits of my knowledge.

[69Customs]

Toploader transmissions are rather noisy. After a rebuild of bearings, pins etc. it may take a while to quiet down. If you just had a noise problem I would write it off to that. But because you have a leaking oil problem. You are sure this oil leak is the heavy 90 gear lube from the transmission and not engine oil? You did use heavy gear lube 90 wt?
If they are over filled and the air vent on top is clogged they can blow tranny fluid.
I run toploader imposter right now and it blew tranny fluid out the speedo gear connection.( I had to use a Ford speedo gear connector and adapt it to a GM cable) so I sealed that up with RTV and it traveled all the way up the cable and started to drip under the dash on my foot, but that was because I overfilled the tranny fluid.
You may want to check some of the Ford forums to see about a fix. sure they have run into it before.
I have a couple 3 speeds lying around and will check the run out on them. I know the one I had in the car never leaked out the nose and it was a used unit.
Most of the used units are in excellent shape cause everyone ripped them out to put in 4 speeds before the 3 speeds were thrashed on.
One other thought would be did you replace the pilot bearing? There is a difference between the ford pilot dia and the GM pilot dia. If he replace the input shaft did he use the GM one or the Ford? There is a difference! Ford is 1-1/16 10 spline GM is 1-1/8 10 spline. A GM clutch will fit on a Ford spline with too much slop but a Ford clutch won't fit on a GM spline. I find it hard to believe he could even find a new GM input shaft being these trannys are not used much. Unless he put a good used one in?

[deserttoolman]

Never even thought about the input shaft differences, I will definitely check into that. That seems like it could potentially be a key issue.

I am pretty sure it is the GM tranny fluid that I put in (90W), but I'll double check.

Thanks!

[69Customs]

The Ford input shaft is 1/2 in. shorter than the GM. Ford is like 6 in. from the face and Gm is 6-1/2 in. Ford has .669/.670 pilot dia where the GM is .590 dia.,but due to shorter length it would be too short to enter into the GM pilot Assy. The only reason I know this is because I run a Toploader and had to make my own pilot bearing extended out extra 1/2 in. or so, then I found they sell these on the internet for this conversion. Of course the shaft dia's are different too on the 10 splines.

The old 3 speed I ran without any problems has like .050-.060 slop, checking this with a dial indicator and moving the shaft left to right. But when assembled in the pilot bearing this slop is void.I checked it on a couple of my used toploaders and it was about the same on all of them. (None of them real tight when out of the car)

There are also articles on the web on how to check a used toploader. Let us know if you find anything out. Hope this helps.