Transmission gears

[pflaming]

Question #1: Are gears 1- 3 in four speed, three speed, and fluild drive transmissions all the same?

Question #2: When a tranny is opened up, how does one determine if a gear is in good condition?

Question #3: Is there any difference in the housing between a three speed and a fluid drive? How about the clutch will a three speed clutch work with a fluid drive tranny?

[Merle Coggins]

1. Gears 2-4 on a four speed would be similar to 1-3 on a three speed. 1st on the four speed is a granny low.

2. If you pull the cover and look inside, look for chiped or broken teeth on the gears, excessive play in the shafts from bad bearings, or any thing else that doesn't look quite right.

3. The transmissions used with Fluid Drive have longer input shafts. The transmissions, whether 3 ot 4 speed, are the same in standard version or Fluid Drive version, except for the input shaft and retainer.

Merle

[pflaming]

Merle: I take your answer to mean that gears 1-3 in these transmissions are alike and then are interchangeable. I did a search on 'transmissions' on the forum but did not learn much from that search. One one post it noted that second gear is the gear that takes the greatest wear. Makes sense. So that would be the gear to check very closely. Reverse then would get the least wear, so that might be the gear to use as the 'standard' for a good gear.

If a tranny has sat for years but had oil in it all that time, it should be as is was when parked. Only a dry tranny would age and that would be by rust. Is that a fair statement? I plan to remove the top, take a look, and then replace and run it. I will have to see something that is obviously wrong before I tear it down.

I have a four speed and a three speed, will use the three speed and keep the other for parts.

[MBF]

I think what Merle meant was that the gear ratios on 2-4 in a 4 speed were similar in ratio to 1-3 in a 3 spd. I'm not sure what if any of the parts are actually interchangable between the two different transmissions. I know the 3 speeds require a different bellhousing than the 4 spd.

[Merle Coggins]

Thanks Mike, that is what I meant. And I agree that it's unlikely that any parts are interchangable between the two trannies.

Paul, do I remember correctly that your truck has Fluid Drive? If so, what trans did it have originally? Like Mike said, the bell housings are different for a 3 speed and 4 speed. And are both your 3 speed and 4 speed trannies made for Fluid Drive with the longer input shaft? And (last question) is the 4 speed a spur gear type, or helical gear/syncronized type? (does the crain plug point straight back or down at an angle)

Merle

[pflaming]

Currently I have a standard three speed, no fluid drive, complete bolted to the engine, and a four speed w/o a housing. I have spoken for a Chrysler engine, 25" block without a tranny. I get that in April, so I have to find a tranny for it. I do not know if my housings will fit the larger engine. It had a four speed but does not at this time.

On a four speed, I always referred to them as super low, 1,2,3, so we are thinking the same, just using different terms. (". . . drain plug point straight back or down at an angle?) Will have to check the drain plug and the gears but seems it won't make any difference, since I am going to use a three speed, it seems none of the four speed will work exchange with a three speed anyway.

Appreciate the information.

[Young Ed]

If you really needed to you can drill the bellhousing for the other tranny. They start out as the same casting and are just drilled to either the 3spd or 4spd pattern.