What's up with the 4sp OD trans?

[motzingg]

I got a chance to grab a good 300 w/ 4sp OD trans attached for pretty cheap. Whats the deal with this trans? I don't hear much about it. Is it any good? Am I better off holding out for the M5r2 like I have been planning?

Does it use the same slip yoke output as the 3 speed? Looks kinda like it does, but maybe with a longer nose or something like that?

[motzingg]

eh ok just found that toploader dude

http://www.4speedtoploaders.com/imposters.htm

he doesn't seem to think much of the 4 speed OD...

pretty sure the 4 bolts and the bulge on the bottom give this one away


nevermind, looks like i answered my own question... more or less junk.

[HIO Silver]

The gear spacing isn't ideal... there's a big drop between 2nd and 3rd or 3rd and 4th.. I forget which. It's not ideal as a "performance" transmission but prolly OK for a daily driver. My neighbor, the pool dude, had an '80 F100 and it has over 320K miles with that trans fronted by a 300. It finally gave up a few months ago... the engine, not the trans.

[Nitekruizer]

It depends on who you ask I guess.
http://www.460ford.com/forum/showthread.php?t=147192

I installed the cast iron "Top Loader" SMOD ( Side Mounted Overdrive ) behind the mildly modified 390 in my truck so, I guess I'll find out who is right. The wide split is between 2nd and 3rd.

Stay away from the aluminum case versions.

[motzingg]

see. this is where it gets confusing, there is a '4 speed toploader' that has a 1.0 top gear, which everyone agrees is f-all bombproof.

There is the 3 speed toploader and the 3 speed 'ford' (my truck has the 3.13 'ford'), which are similar but the true 'toploader' borg warner is stronger.

then there is the 4 speed OD which is apparently a 3.13 with an overdrive 3/4 gear smashed in where the 3'rd would usually go, this is known as the RUG from the casting mark.

then there is the SROD single rail overdrive which looks similar but has the lever mounted to an enclosed rail that runs to the rear of the trans (fox body mustangs) which i think is the 'aluminum' one that you're talking about.

so this 'blown 473' guy is saying that there is a 4 speed OD that is sturdy, but he is saying '73-'87, where as the 'RUG' David Kee says was only '77 and '78.

The trans i'm looking at appears to be a 'rug' based on how the linkage mounts and the bulge on the side, but is there a different '4 speed od' which is known as SMOD as opposed to the one with the bulge on the bottom?



I guess the thing that i would be concerned about is the 3/4 cluster, and the wide 2/3 split. I'm really hating life shifting the 1/2 on my 3.13 at about 7 mph.... super annoying.


I think i'm pretty much convinced that the extra hassle (hyd. clutch, trans hump, driveshaft, possible crossmemeber complications) is worth it for the M5R2

[Nitekruizer]

Yeah, it does get confusing. I wish they were all as strong as the original 4-speed Top Loaders.

Here's what I can tell you. The cast iron overdrive "Top Loaders" were all SMOD's. S.M.O.D. stands for Side Mounted Overdrive which refers to the external side mounted shifter with external linkage. There are also two aluminum case transmissions, one of them is called an SROD (Single Rail Overdrive) and the other is known as the TOD. The TOD has the shifter coming out of the top of the trans like the shifters are on T-18's, etc. In trucks, the cast iron SMOD was used in 1978. From 1979 to 1984 the aluminum SROD was used for the first few years and then the TOD was introduced. I don't believe either of those were used after 1985 though.
My tranny came out of a 1978 F-Series that had a V-8. The lower gears are a bit low. First is 3.29:1 and second is either 1.87:1 or 1.84:1. Third is 1:1.

Here's what I've been able to find out and believe to be true, but can't base on personal experience. The SMOD is stronger than the aluminum trannies, but not as strong as the real Top Loaders. Makes sense. I believe all of the SMOD trannies were "RUG-**".
SMOD's were also used in cars from around 1973 up into the late seventies or maybe even into the '80's. I have never seen one, but Granada's and Monarch's were some of the cars that supposedly used them. The versions of the cast iron SMOD's that were used in cars apparently had smaller bearings than the truck versions. The truck versions are supposedly stronger.

Yeah, if you are going to use the tranny for high performance or hauling heavy loads or you just want nicer ratio's, the M5R2 sounds like it might be a better choice. I just was looking for the least expensive way to get a floor shifted overdrive behind my FE. I don't plan on hammering my tranny too hard, just cruisin', some city and highway driving and a bit of light duty hauling.

I hope this helps.

[PetesPonies]

I have one. It's basically a 3 speed with OD. I put it in my '79 with a 300. I lie it a lot better than the 3 speed. It has the shifter coming out of the top, so a nice floor setup too.

[timmytim]

I have one of those srod trans sitting in my garage. Decided to for go install do to the ratios gaps...But the bell can be used with t5s and the mechanical linkage

[guhfluh]

I swapped my t-18 out for a T-170/RTS/TOD. Gears 1-3 in the TOD are the exact same ratio as 2-4 in the T-18. The T-18 has a granny low 1st gear and the TOD had an overdrive 4th. The 2-3 shift in the TOD sucks and the 3-4 shift in the T-18 sucks. Everyone loves the T-18 and hates the TOD. Go figure. I'd much rather a TKO.

[motzingg]

yeah i gave up on this particular pipe dream for the time being, gonna stick with the more common mazda 5. plus there are lotsa times when you are hauling loads that you end up having to drop to 3rd, with the SMOD you'd be stuck dropping down to 2 if you cant pull 1:1 and that would suck.

everyting is on hold until after i move, hopefully these things are as easy to come by and cheap in texas as they are in NC. the one that was pulled and ready to go out of a wrecked truck for $150 would have been a good snag.