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bluebird90 07-16-2015 12:40 AM

Swapping trans
My bus came with a DT466 and spicer 5 speed. I want to upgrade to a 6 or 7 speed overdrive. Has anyone done this?
I know you need to shorten the drive shaft. I will be getting a new clutch, maybe an easy pedal. Any recommendations on what trans to use? Really not interested in split shifting or anything like that.

jazty 07-16-2015 10:34 AM

I'm looking to do the same thing. The Spicer 7-speed should be an easy upgrade from the 5-speed. Judging entirely from images on the internet the 7-speed appears to be a bit longer than the 5-speed, but the mounts are identical. I've read that the gears are close, though and even experienced drivers occasionally push into the wrong gear.

I'd be ok with a 2-speed differential if I could find one that also had a diff-lock.

ii_amnt 07-17-2015 01:27 AM

I have that same combo, I can definitely see why you'd want to upgrade. If I wanted to do more road trips with it, I'd be looking into it for sure. How fast can you get going down back roads before you are feeling like you're pushing the engine a little too high in the rpms? I get feeling uneasy passed 55mph. But, I coasted down a big hill going 60-65 and it felt smooth as butter.

nat_ster 07-17-2015 11:09 AM

Check your gear ratios in the 5 speed, then in the 7 speed.

You may not have any higher speed in the top gear. Many 7 speeds only have less RPM drop between gears, keeping the engine in the peak power when pulling hard.


jazty 07-17-2015 12:21 PM


Originally Posted by nat_ster (Post 116556)
You may not have any higher speed in the top gear. Many 7 speeds only have less RPM drop between gears, keeping the engine in the peak power when pulling hard.


Yep, that's exactly what I'm going for. I'm governed at 105km/h (65mph), which I'm perfectly happy with, but the spread between 4th and 5th gear is too much.
I'd also like to get a lower reverse gear since the one in this transmission is way to high. It's about the same ratio as the 2nd forward gear. I have to constantly slip the clutch so I don't go careening into objects behind me.
Realistically, a 2-speed rear could solve all of my problems. They don't seem as common these days, though. Were they really all that bad?

nat_ster 07-17-2015 03:42 PM

The two speed rears were great. I liked them.

It was the lack of people shifting them properly that sucked.


jazty 07-17-2015 03:50 PM

I've not driven one, but I've read enough that I think I get it. Basically don't be a dumbass and try to shift under load; watch your rpms. :) Just like every other transmission without synchros. Seems easy enough. As mentioned above, if I stumble across a 2-speed with a diff lock I'll be jumping on it. Actually, I think all those fancy contraptions are within the carrier, no? It'd be prime if I could swap that out, do all the axle seals and retain my brakes (especially since I just ordered a new rotor).

nat_ster 07-17-2015 03:56 PM

You will need the whole 2 speed rear.

The electric shifter motor is mounted high on the pumpkin beside where the pinion enters the diff.

The pumpkin has castings that take the shaft and mount the shifting motor.

The down side is most had low gears. Low and vary low.

IMO the 7 speed trans would be a better option.


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