Toploader Experts....

[Fabulous50s]

So I have sourced and bought an iron case side mount overdrive (smod) transmission from a Granada.

Got it all torn apart for a rebuild.

It has the short 24" mainshaft. My Galaxie 3 speed toploader has a 27" mainshaft.

Does anyone know if a regular 4 speed toploader main shaft is the same as the OD unit? I'm looking for a 28 spline 27" 4 speed shaft.

Here is my 3 speed shaft and the 4 speed overdrive shaft for comparison.

I can cut the two shafts and weld&sleeve them together.....but that is the last thing I want to do. The other option is have a longer driveshaft made, but the short tail tailpiece for the OD unit also has the speedo drive on the passenger side. So a longer main shaft is the easiest solution so far.

[brushwolf]

Ambitious project... Been a very long time, but I have rebuilt a few toploaders and I have a couple of the OD ones as well.  My sketchy recollection is that the OD toploader has a similar case,, but almost everything inside is different.  David Kees told me that the gearset and power transfer path in the OD toploader is completely different and that is why they cannot take the torque a normal toploader can.

Check with him, if he is still in business.  If it was me, I would just get a longer driveshaft and speedo cable. Or else find a T85 for it which will probably cure the drives haft and speedo issues as well as being a much stronger trans than the OD toploader.

The first 3 gears in the OD toploader are pretty much the same ratios as your 3 speed or a T85. So all you gain is the OD and you may well lose some measure of torque tolerance. Even a T86 probably has as much torque tolerance as the OD 4 speed. So, the only gain is the OD gear which both the T85 and T86 in OD versions can give you also.

[SkylinerRon]

The T/L OD uses a different case than the regular T/L. There is a bulge on the side to clear a large diameter gear in the former 3rd gear position..

The OD unit swapped positions of the 3rd & 4th gear, 3rd becoming OD and 4th being 1to1. Very novel approach  for a quick OD from existing parts. Mopar did the same thing to their A-833 4 sp. as buyers were looking for gas mileage in the mid 1970's.

Most of those OD's had a 2.99 1st and a big drop between 2nd and 3rd gears.

I would think that a 27" long output would work but, you'll need to get one to compare and check on the tailhousing too.

The 24" trans has the shifter mount in the wrong place and the trans mount too. If in fact all of this does work you will need a 64-68 Galaxie T/L tailhousing to make it work.

Good luck,

Ron.

[Fabulous50s]

I have the correct long tail housing, what was bolted to the '69 toploader which was in the car when I bought it.

I actually looked for a T-85 and an R11 O/D for several years. Anyone who has one (none locally) wanted well over $1,000 for a used unit which I'd have to rebuild.
Too rich for my blood.

The whole point of this is to retain the column shift and have O/D. Only way I saw that happening is with this or a T-85. Otherwise I'd absolutely do a floor shift and a 5 speed.

I've called and emailed Dan Williams, David Kee, and Toploader heaven. No one has answered the phone or emailed me back. Leaving me a bit frustrated to say the least.

Just for fun I graphed out my existing close ratio with my axle and 14" wheel/tire combo.

As well as the "car O/D" trans which I want to install and the "truck O/D" which is slightly different ratios. I find everything about the car O/D ratios desirable. Lower first and more even spacing than the truck unit. I have to ride the clutch much more than I'd like with my close ratio and 2.91 gears.

[lalessi1]

Here is a pic of a 27" main shaft you can compare. It does have the 31 splines but it might tell you if what you are trying to do is feasible. Does not look the same to me.

https://www.ebay.com/itm/66-67-FORD-TOP-LOADER-MAIN-SHAFT-31-SPLINE-4-SP-FULL-SIZE-CARS-427-428-WT296-2D/352745214191?hash=item522140d0ef:g:wtcAAOSwKs1dSKkD

[81TTA]

...David Kees told me that the gearset and power transfer path in the OD toploader is completely different and that is why they cannot take the torque a normal toploader can...

Did he go into any further details about that?  As mentioned, the first 3 gears are just about equivalent ratio-wise to three-speed TLs.  If there's a lower torque capability in the OD units, I'm guessing it's because they changed either the dimensions of the gears (i.e. narrower?) or the materials they used?  I can understand OD 4th gear being generally weaker due to the reverse multiplication.  I don't understand why the torque capabilities in any other gear wouldn't be largely the same.  To my knowledge, the power transfer path is identical in all the TLs.  If we're talking about a reduction in torque capacity of something like 10-20 lb-ft compared to non-OD, I guess that makes sense.  The impression I get from reading your (and other) responses seems to be that the transmissions aren't worth installing compared to T-85 and non-OD TL.  Curious if that's from actual testing/measurement or just something "everyone knows" because they read it on the internet!

...As well as the "car O/D" trans which I want to install and the "truck O/D" which is slightly different ratios. I find everything about the car O/D ratios desirable. Lower first and more even spacing than the truck unit. I have to ride the clutch much more than I'd like with my close ratio and 2.91 gears....

I had one of these installed behind an FE with a 3.00 rear end.  With the car ratio first gear of ~3.27, it made a world of difference on launches.  No need to slip the clutch nearly as much as with the wide-ratio 2.78 first gear.

...The whole point of this is to retain the column shift and have O/D. Only way I saw that happening is with this or a T-85. Otherwise I'd absolutely do a floor shift and a 5 speed. ...

So....  You have a 4 speed column shift?  Doesn't the T-85 use the column to select gears 1-3 and a separate cable to engage the OD gearset?  How are you going to choose between 5 gears (4 forward and reverse) with the column shifter?  Just use it for "forward" gears and do something like the cable for "reverse"?

[Fabulous50s]

I plan on using a PTO cable with a rack and pinion lever under the dash for reverse. All toploader transmissions have interlocks to prevent more than one gear from being engaged at once. I was originally going to fabricate a 3rd shift arm on the colum to have all 5 gears on the colum. But I installed that column after having painted everything on the interior and dont want to pull it all out again.

[Fabulous50s]

I've found a 27" 4 speed main shaft. However I cannot find one with 28 splines to fit my slip yolk.

My question is, what is the outer diameter of a 31 spline slip yolk? Maybe....just maybe....it is the same and I'll just change the main shaft and my slip yolk and be able to use my long tail housing.

Otherwise, I can always have a longer driveshaft made, but I'm thinking this is the cheaper option and I dont have to mess with the speedo cable.

[81TTA]

From a quick search on the web, the diameters are different :

28 spline : 1.5 inches
31 spline : 1.685 inches

[59meteor]

I have no personal experience with the 3 speed OD Orion Toploaders, other than driving a few, and years ago, I owned a Plymouth Volare Road Runner with the Chrysler equivalent 3 speed OD A833 transmission, and for cruising around they were OK, but the large ratio drops between gears was awful. Can`t report about strength, as although both my Volares 318 had a cam, headers, Edelbrock intake and Holley carb, as did my buddys 351W with the Ford trans, neither car was raced with slicks. But both cars pulled strong in 1rst gear, but the 1-2 shift dropped the RPM so much, it took quite a while to allow the engine to get back into the power range, same with the 2-3 shift. Now, if you plan to just drive "normally", likely not a big concern. Now, I have no idea if a Toploader 4 speed mainshaft is interchangeable or not, but I believe there are (at least) 2 different 31 spline mainshafts. I still own a NOS shaft, but I had a guy interested in it, but he said the location of the speedometer gear was in the wrong place. Supposedly, the Galaxie and Torino shafts were the same overall lengths, but the machined area where the plastic speedo drive gear mounts is different. Just one more thing the check into.

[Fabulous50s]

The biggest difference I see is the physical size (width) of the actual gears. The 3 speed I have the gears are about 1/3 wider than the OD unit. Otherwise they are the same. Same synchronizers, blocking rings, and the front and rear bearings are considerably larger in the OD unit.

I can see the weakness in the OD gear as it puts a lot of strain on the counter gear and counter shaft. I'm replacing the counter shaft and all bearings etc.

Gears 1-3 are the same as a wide ratio toploader. My close ratio toploader requires a lot of clutch slipping in 1st or reverse on a hill. I'm looking forward to a deeper 1st and reverse.

I can get exact measurements and locations of the OD main shaft if anyone has one to measure and see if they are indeed the same.

I'm wondering if I can machine my tailpiece to accept the larger 31 spline bushing and seal, and just change my slip yoke.

[lalessi1]

The tailshaft  housing on a toploader 4 speed can be machined out to convert to a 31 spline mainshaft.

[81TTA]

...But both cars pulled strong in 1rst gear, but the 1-2 shift dropped the RPM so much, it took quite a while to allow the engine to get back into the power range, same with the 2-3 shift. Now, if you plan to just drive "normally", likely not a big concern....

Now that I completely understand.  That was the motivation to put the wide-ratio transmission back in.  Just can't quite get the best of both worlds with these 4-speeds.  OD has better launch and highway cruise.  Non-OD much better gear spacing.  Now, the hunt is on for a TKO 5-speed!

...I can see the weakness in the OD gear as it puts a lot of strain on the counter gear and counter shaft. I'm replacing the counter shaft and all bearings etc.  Gears 1-3 are the same as a wide ratio toploader....

I can understand that.  If the statement that the OD's are weaker comes from someone doing a 5000 RPM launch in 4th gear and breaking stuff, I guess I can see that.  Or, that their supercharged, nitrous 1,000HP engine managed to grind the transmission to dust when they floored it in 4th when they tried passing someone on the highway.  I really think the confusion comes from all the various OD transmissions that were made around that time.  People are conflating all the various OD offerings into one group.

...The tailshaft  housing on a toploader 4 speed can be machined out to convert to a 31 spline mainshaft....

I haven't found any information on the bushing OD sizes between the two.  I would imagine there would be enough material to allow the tail housing to be machined for the larger shaft.  As far as the seal goes, my guess would be that the seal OD of the 28 vs 31 would be the same while the ID is different for both.  Is there a chance that the seal OD is larger on a 31 spline housing?  That area might need to be machined, too?

[lalessi1]

I have a friend who is in the gear business. He has upgraded a few Toploaders from small input/output to the larger size. The castings are the same, for the rear 31 spline the tail housing needs to be machined to accept the larger bearing but ( if I remember?) the seal is the same. I can double-check with him before you spend any money. This guy has a warehouse FULL of old trannys and third members for almost anything.

[Fabulous50s]

I was finally able to reach Dan Williams (toploadertransmissions.com) and he was boardeline rude about me having an ugly car and wanting to put an O/D in it. He was absolutely no help whatsoever and told me that the O/D transmission had no parts in common with real toploaders. I know this isnt true, as I have a real tooloader and this O/D both apart in over half of the parts are identical. And will directly swap.

Dont want to give a poor review but that was my experience.