Allison 6 speed transmision?

lotzagoodstuff

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I never built a slug. Garbage Equipment is in a drag race all day long!

Spec'ing a refuse truck takes a lot of knowledge. I've seen municipalities spec CNG trucks with "all the heaviest pieces because they wanted them to last long", and of course because they were spending other people's money :eek:.

Apparently a 4000 series Allison with the wrong rearend gears will produce a road slug.
 

6thGenIDPioneer

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Maybe this isn’t relevant... I have a ‘92 F-350 quad cab, long bed, 4x4, IDI or DI? ATS turbo, 1:4.10 gears. 5 speed manual ZF.
I haul 3 cord wood through Idaho mountains and it does great. Keeps up with my buds ‘97 F350 powerstroke automatic no problem. Better tower for having 5 speed. Still I could see benefits to having more gears. Sounds a little expensive for the benefit though. FYI... when reversing, put T-case in 4Low. No need to lock in hubs. T-case acts like 2speed splitter. Makes reverse (and all gears) lower. A lot of what I do has me riding my clutch like a SOB otherwise! I keep wearing out the bushings in the pedal assembly and getting tons of slop. New assembly is $150 for the part and it’s not going to be a quick job. $750 minimum for a shop to screw it up. And that’s if you can find one that’s even willing to take that on. Didn’t Ford(or whoever) make a 6speed manual for the 7.3 powerstroke after 2000ish...? Would that fit the IDI and frame of the OBS? As well as B-W T-case while keeping the drive axles? Let me know if you’ve done or seen this.
 

chillman88

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Didn’t Ford(or whoever) make a 6speed manual for the 7.3 powerstroke after 2000ish...? Would that fit the IDI and frame of the OBS?

They did, and it can be made to fit, but it's not a direct bolt in. Something about needing an adapter for the engine or something like that.

The only benefit from the 6 speed is another gear in the middle somewhere, maybe between 3 and 4? I don't remember.

Short story is the ZF6 is not really worth the fuss to swap it in sadly.
 

Farmer Rock

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Maybe this isn’t relevant... I have a ‘92 F-350 quad cab, long bed, 4x4, IDI or DI? ATS turbo, 1:4.10 gears. 5 speed manual ZF.
I haul 3 cord wood through Idaho mountains and it does great. Keeps up with my buds ‘97 F350 powerstroke automatic no problem. Better tower for having 5 speed. Still I could see benefits to having more gears. Sounds a little expensive for the benefit though. FYI... when reversing, put T-case in 4Low. No need to lock in hubs. T-case acts like 2speed splitter. Makes reverse (and all gears) lower. A lot of what I do has me riding my clutch like a SOB otherwise! I keep wearing out the bushings in the pedal assembly and getting tons of slop. New assembly is $150 for the part and it’s not going to be a quick job. $750 minimum for a shop to screw it up. And that’s if you can find one that’s even willing to take that on. Didn’t Ford(or whoever) make a 6speed manual for the 7.3 powerstroke after 2000ish...? Would that fit the IDI and frame of the OBS? As well as B-W T-case while keeping the drive axles? Let me know if you’ve done or seen this.
Your truck being a 92 is an IDI (assuming it's original).I believe the OP has a 2wd truck, so he can't just throw it in low range. Like @chillman88 said, it's not really worth the zf6 swap. I am not sure if the zf6 even has a lower reverse? But even if it does, I can't see it being worth the trouble even then. I think if a guy was desperate for more gears, a brownie box is probably the way to go if you can find one.



Rock
 

Booyah45828

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Reverse in the zf6 is 5.29 vs 3.79 in the idi zf5. The power stroke zf5 is a wider split then the IDI version, which gives you a little better reverse and 1st ratio. It's also a direct swap I believe. There is a gas version zf5 out there that gives you even wider ratios then the powerstroke zf5, not sure if anyone has tried one out behind an idi though, or if it's a nuts and bolts swap.
 

lotzagoodstuff

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There is a gas version zf5 out there that gives you even wider ratios then the powerstroke zf5, not sure if anyone has tried one out behind an idi though, or if it's a nuts and bolts swap.

Russ has a gasser ZF5 in his white truck, there’s a couple of things you have to do to the bell housing to make it IDI bolt on, I think the bottom holes need to be drilled but the top bolts line up, pretty sure it’s documented with pics on here.
 

IDIBRONCO

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From what I was told, the ZF6 had a lower 1st gear. That way they could run higher axle ratios to help with fuel mileage. The 460 ZF5 isn't quite a direct bolt in swap. Some of the bellhousing bolt holes will need to be redrilled.
 

71 Highboy

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I have used a GV unit between a C6 and a remote NP205 for 19 yrs. The company reps have changed, but the do and don'ts have not. They operate on a little over a quart of fluid, so use good synthetic, like Lucas, and change every year or 10,000 miles. Don't use it engaged for compression braking down hill. Lite throttle downhill is better, or disengage to direct drive. I have replaced it twice because of cone clutch failure. Very rarely use it in the auto mode, as I prefer to shift it in and out manually as conditions require. Only shift in and out under power, especially on the disengagement. They are hydraulic actuated, very similar to the British od made by Leycock. There were some IDI/Allison combo's installed as drive train in some bus models back then that were all manual. Hard to find and they were direct drive, so u didn't gain much except an in between gear.
 

subway

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Both options are going to be $$$
The allison will need the international sae2 or 3 flywheel housing with matching adapter flywheel (not flexplate). A big external cooler (usually water/oil cooler). A means to down size the driveshaft. Probably need a body lift and some firewall massaging, a custom crossmember, and a batch of other modification and fab work to get everything setup right.
After that you also need to have the TCM programmed (if you have a allison dealer nearby they should be able to do this) how you want it and insure you have the correct speed stall on the torque converter (there's a whole batch allison makes for this) to benefit your pump/turbo setup.

having put a medium duty transmission in my IDI I can tell you that a SAE2 bellhousing can fit with the transmission and no body lift. The rest you are spot on about with the cross member and driveshaft. I just made a ******* drive shaft with a 1600 (I think) joint on one end and a 1350 joint on the other. It looks crazy but it runs smooth.
 

jrollf

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Your truck being a 92 is an IDI (assuming it's original).I believe the OP has a 2wd truck, so he can't just throw it in low range. Like @chillman88 said, it's not really worth the zf6 swap. I am not sure if the zf6 even has a lower reverse? But even if it does, I can't see it being worth the trouble even then. I think if a guy was desperate for more gears, a brownie box is probably the way to go if you can find one.



Rock
Correct, my beast is 2WD... but throwing in a t-case just to get "low range" is something I have considered.

1993 F350 Crew Cab Dually
7.3L IDIT with a Banks Sidewinder
ZF 5-spd manual transmission
 

IDIBRONCO

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Correct, my beast is 2WD... but throwing in a t-case just to get "low range" is something I have considered.

1993 F350 Crew Cab Dually
7.3L IDIT with a Banks Sidewinder
ZF 5-spd manual transmission
I'm going to be doing this to my Ex Wife for the low gear. Well that and all I have is 4X4 ZF5's.
 

IDIBRONCO

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No. All I've got is two. One for each truck. I'm actually looking for another one to have on hand just in case. I'm just not looking very hard yet.
 

BrandonMag

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What ya'll think about the idea of putting an Allison 1000 or 2000 series 6 speed transmission behind an IDI? The conversion to the Allison would not be cheap... what ya'll thoughts on it?

I think it's a great idea.

However, the main reason that most of us on this forum choose to drive old IDI-powered Fords is this: they're cheap to own and fairly simple from a mechanical standpoint. Most of us that drive these trucks spent some time on craigslist (or FB Marketplace or wherever), found a reasonably priced IDI, bought it, did some basic (and sometimes not so basic) maintenance, and now own a relatively reliable truck that will do most things necessary for most people. Swapping an Allison in blows that approach out of the water: it ain't going to be cheap or simple. You'll be buying a new transmission, all of the associated hard parts to make the conversion work, installing the transmission and all of the hard parts and then you'll need to program the TCM to make the transmission work properly. Another option would be to have a shop do the swap, but then you're back to another option that most of us on OB aren't fans of: paying someone else to do the (hopefully quality) work on your truck. I think this is diametrically opposed to the fundamental choice most of us that drive IDIs either explicitly or implicitly made at the time of purchase: cheap and simple.

I want to be clear: I am not saying you should not do this swap. If you decide to make the leap I will read the thread you post and give you support or ask questions just like most here. My hope by posting this is to get you to spend some time thinking hard about the scope and cost of the project you're suggesting before moving forward with it.
 
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jrollf

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I highly doubt I will go down this path, more of a daydream due to the cost. If anything I would more likely go with a Gearvender and possibly throw in a t-case to get low range.

1993 F350 Crew Cab Dually
7.3L IDIT with a Banks Sidewinder
ZF 5-spd manual transmission
 
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