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That does make sense why I was having so much trouble with skipping shifts. I had the SAE2 flywheel with a huge dual disk clutch. I found a good deal local and couldn't resist....

Makes sense why it would take so long for the RPM to drop.

Thanks Blackduck!

I don't know about not having a clutch brake. Mine would keep the gears spinning no matter what until I hit the brake. No amount of time would stop the gears.
 

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That does make sense why I was having so much trouble with skipping shifts. I had the SAE2 flywheel with a huge dual disk clutch. I found a good deal local and couldn't resist....

Makes sense why it would take so long for the RPM to drop.
A dual-disc is heavy. You get the similar slow-shifting running a dual-disc with a Dodge transmission.

SAE3 is not very common with a manual (common with allison auto though.) Even the direct 5spd (Fuller) my buddy got from a 4BT freightliner van was SAE2 (single disc).

Most of the extra mass with SAE2/SAE3 is the flywheel and pressure plate - and that's on the engine side.
 

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A dual-disc is heavy. You get the similar slow-shifting running a dual-disc with a Dodge transmission.

SAE3 is not very common with a manual (common with allison auto though.) Even the direct 5spd (Fuller) my buddy got from a 4BT freightliner van was SAE2 (single disc).

Most of the extra mass with SAE2/SAE3 is the flywheel and pressure plate - and that's on the engine side.
Yes, and if your floating gears, that inertia is all locked together with the clutch plate/transmission shafts - slowing the engine rpm drop.
 

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Flywheel/clutch mass certainly comes into and as well as the engine mass. Late 70's here International started putting RRs behind the petrol V8.
Had to shift those different to the diesels. You could also tell the difference with the Cummins 6's, V8's and the Detroit Diesels. All just a little different.
Cheers Steve
 

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Yes, and if your floating gears, that inertia is all locked together with the clutch plate/transmission shafts - slowing the engine rpm drop.
True enough! ...and at that point, the tach is telling you the clutch disc speed. :wink2:
 

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Counter shaft brake

Weathers been lousy, managed a couple of pic's. The spare trans does not have a brake to pull apart.
Weather fines up a bit I can pull the outer cover and get the diameter of the piston. That actual shaft size will be a bit of a guess but could go off the gear width the brake runs on.
Cheers Steve
 

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I've been waiting for the opportune time to yank the bed off my truck and put the Mitchell Hi/Low box I have behind my 5spd. It's a 12% Under/18% Over all aluminum box rated for 30K gross so plenty strong for our trucks.

Anyone know of a fab shop in San Diego good with drive lines?
 

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I've read about that being a issue and not sure what Aux others have used. To me with mine on a jack as close as I can get it but obviously too low it looks like it will clear fine.

I'm going to start collecting the parts needed and eventually give it a go mounting it. Right now I need another output yoke and then a huge u-joint as it was is a medium duty truck. Also thinking about shifting it and might go electric.
 

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Just ran into this thread and had a thought (happens once in a while)...you don't mention what your application is for the truck. Are you hauling all the time and what kind of weight? For all the potential modification you're talking about, although fun to do, is there a simpler path? I haul intermittently up to about 16K and hated the Getrag, especially 3-4, so when I rebuilt I went with a Southbend clutch and GearVendor OD. 'Course it required cutting the driveline, and the GV won't work in 4WD, but it works 100% better for what I do (farming mostly, hauling equipment and product). I also find it great when I'm not hauling and on the hiway, it is smooooth in 5th OD at 75mph (4.11 gears). Oh, '93 W250 with mild changes including slightly larger injectors, pump bump and turbo adjustment. As I said...just a thought.
 

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Why bother with two 5 speeds glued together?

Friends don't let friends use synchros.

Synchros are only acceptable on air splits.

Float a 13 speed's physical shifts & have fun.

Real trucks use transmissions that don't have to spool the turbo/s between shifts, but that's a story for another day.
 

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Discussion Starter #53
Just ran into this thread and had a thought (happens once in a while)...you don't mention what your application is for the truck. Are you hauling all the time and what kind of weight? For all the potential modification you're talking about, although fun to do, is there a simpler path? I haul intermittently up to about 16K and hated the Getrag, especially 3-4, so when I rebuilt I went with a Southbend clutch and GearVendor OD. 'Course it required cutting the driveline, and the GV won't work in 4WD, but it works 100% better for what I do (farming mostly, hauling equipment and product). I also find it great when I'm not hauling and on the hiway, it is smooooth in 5th OD at 75mph (4.11 gears). Oh, '93 W250 with mild changes including slightly larger injectors, pump bump and turbo adjustment. As I said...just a thought.
I think I have decided on an easier way. I think what I'm going to do instead of a 10 speed which is out of my price range, is install a 4 speed Muncie SM420 behind the Getrag 360. I'll primarily be using 3rd and 4th in the SM420. If my Math is correct, 3rd should essentially split my gears in half coming out of the Getrag. Then to 4th in the SM420 for direct. I already have about 5 of these laying around and I work in a shop where we are constantly building/rebuilding driveshafts so that won't be an issue. I'll have to rig up a bearing for the front of the input shaft on the SM420 but I think it'll work for me.
 

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I think I have decided on an easier way. I think what I'm going to do instead of a 10 speed which is out of my price range, is install a 4 speed Muncie SM420 behind the Getrag 360. I'll primarily be using 3rd and 4th in the SM420. If my Math is correct, 3rd should essentially split my gears in half coming out of the Getrag. Then to 4th in the SM420 for direct. I already have about 5 of these laying around and I work in a shop where we are constantly building/rebuilding driveshafts so that won't be an issue. I'll have to rig up a bearing for the front of the input shaft on the SM420 but I think it'll work for me.
Depending on your hp range I don’t think the 420 is a good idea. They are plenty strong for a small block Chevy and plenty of guys have broken them behind a 454 now with the torque of a 5.9 I would be worried especially with the torque multiplication of your factory trans. But still, sounds like a cool project I’m interested to see how it works out.
 

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Discussion Starter #55
From what I've heard, it's usually the input shaft of the SM420 that gives trouble. Depending on how complex it is, I might be able to build a bigger one that will take the torque. Either that or modify the existing one to help mate to the other transmission, shortening in the process and hopefully getting away from the weak points.
 

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From what I've heard, it's usually the input shaft of the SM420 that gives trouble. Depending on how complex it is, I might be able to build a bigger one that will take the torque. Either that or modify the existing one to help mate to the other transmission, shortening in the process and hopefully getting away from the weak points.
Yes the one I broke in my old chev was the input shaft.
 

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Back in the day they put under drive and over drive boxes in 10 wheelers. If I remember correct brownlight made them. You might be able to find one in a old big truck junk yard. A buddy of mine has one in his pile but I think it is only a under drive. They should handle the touqe.
 

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Back in the day they put under drive and over drive boxes in 10 wheelers. If I remember correct brownlight made them. You might be able to find one in a old big truck junk yard. A buddy of mine has one in his pile but I think it is only a under drive. They should handle the touqe.
I think your talking about a browny box. Those are great and I believe can even be had with overdrive so you could have a low/direct/Overdrive the only downside is they are big/heavy and aren’t synchronized. I’m fairly certain they come in 2, 3 and 4 speeds.
 

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Discussion Starter #59
I'd be fine with just under and direct. I can go 60 at 2000 rpm in 4th. Obviously I don't pull in overdrive but 60 is fine with a trailer for me. I haven't found a Brownie yet but if I can find one on the cheap, I might go that route.
 

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I think your talking about a browny box. Those are great and I believe can even be had with overdrive so you could have a low/direct/Overdrive the only downside is they are big/heavy and aren’t synchronized. I’m fairly certain they come in 2, 3 and 4 speeds.
My dad runs a browny box in a 1 ton Chevy service truck he has. I have contemplated putting one in my truck
 
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