I posted this on the pre-85 truck forum but got no responses at all, possibly because the audience was too limited. So, I'm posting it again on this larger forum hoping someone has some info:

I have a 1983 Toyota Dolphin motorhome that came stock with a W42 4-speed manual transmission and a 22R engine. A previous owner replaced it with a W50 5-speed which is geared way too high for this heavy vehicle. I need to have the W50 pulled for repair anyway (pops out of 4th) so I figure now would be a good time to replace it. I've got a line on a rebuilt W59. I've gotten the general idea from this site that all W-series transmissions are interchangeable on any R-series engine. I'm hoping some one here has actually made this swap and can tell me whether it really is a simple bolt-on operation or whether there are likely to be "surprises". Anyone?
-Steve

 

Don't know; but I have a what I think is a W54 4spd that was behind a 22R in a 1987 PU. So I guess its true, any transmission in a storm. Just watch the drive shaft.

 

Thanks Skypilot. I wonder if yours is actually a W45 rather than a W54. I couldn't find any W54s listed but they did make a W45 4-speed. I'm almost tempted to just take a chance and get the W59 and hope it works. But, if it doesn't, it's a pretty darn expensive mistake to make.

-Steve

 

As far as I know all the 4 speeds run direct in 4th gear.

The 5 speeds also run direct in 4th gear.

I don't have all the tranny ratio specs in front of me, but I've never seen a Toyota 4 speed with a super-low 'granny' first gear.

Is the W42 tranny that you desire such a granny gear tranny??

If not, there's likely little difference in trannys that will help you with your under powered rig. You might as well just run the tranny you have in 4th gear.

Maybe what you really need is a lower gear in the rear end.

Edit: I failed to notice that your 5 speed needs repair, but my point is still valid.
With a lower final drive ratio, you could make use of 5th gear; at least some of the time.

 

I'm not actually looking for a 4-speed, Millball. My rig came with one originally but someone changed it to a 5 speed from (primarily) a Celica. Looking at the specs on the 5-speeds on http://en.wikipedia.org/wiki/Toyota_W_transmission, it looks like 4th gear in the 5-speed is also direct (1.00:1) but 5th gear is actually geared even higher like 0.8XX:1. But regardless of that, what I would like is something like the W59 which comes with this description:
"1st and 2nd are low ratios like in the W56 for use to get a heavy vehicle moving.
3rd ratio is the same as in the W57/W58 for a lower rpm drop between 3rd & 4th useful in high-speed acceleration.
4th is direct 1:1 as per design in these boxes.
5th seems to be the base W55 overdrive ratio."

And you're right, it might be that I could repair and keep my W50 and just change from a 4.11 to a 4.56 rear end and achieve what I'm looking for.
-Steve

 

The wiki seems to indicate that all the 'W' trannys bolt to the same bell housing bolt pattern.

Wether or not the input shaft length is compatable with your bellhousing??? IDK

Maybe Hollander interchange might tell.

Looks like the W59 has the slightly lower first and second gearing that you
seek.

W56s' are not too hard to find, and appear to have similar characteristics.

Are they asking a top dollar price for the tranny you have found??

 

What's "Hollander interchange"?
All the W56 and W59s I've seen are running from $650 to $950 or so, with a 90 day warranty. Unless I get a rebuilt one from Marlin Crawler where they want closer to $1100. The rear end change may be the smarter and more economical move.

 

Gigantic database of interchangeable auto parts.

Befriend an auto salvage guy. The database costs $$$