O/D VS Non O/D

[andyh1956]

Greetings from Mississippi!
Can anyone tell me if the non O/D transmission (Spicer 6352?) is a direct exchange for the Spicer 3053A? I think that's what my A2 has in it.
I do not like my 1st gear ratio & do not need an overdrive. When I get my crane removed I want to drag my backhoe around & the non O/D trans would suit me much better. I am having to use my transfer case in low range sometimes to get rolling & that just seems stupid to me.
I thought about something more modern but modern transmissions are much longer & my truck is "Space Challenged" around the trans / transfer area.
I have a Spicer 5052 trans in an old Loadstar but that is a BIG transmission!
Thanks!

 

[tobyS]

Hi andy...that's a good question.

Your post caught my attention because the Allison in my M35A3 is 1/1 and I wish I had the OD. I'm thinking about axle gears 4.90.

It sure would seem like the older non-OD should fit. How about an Allison 545?

Post up what you find.

Edit....if you find it fits, make a wanted ad and offer to trade your tranny. Maybe a guy with a bobber has a non-OD that wants the OD.

 

[andyh1956]

Thanks. I am not a fan of the 540 series of Allisons.
Back when these were installed in the S series IH & the F series Ford Trucks they would not stay behind a 210 HP 3208 Cat engine. After building a good number of these it struck me that these were just 4 speed Turbo 400s! If Taylor & Jeans in Jackson built one & found out it was going behind a Cat they would stamp the repair order "No Warranty"!
I had a 645 & I gave it away for a core & it wound up in their scrap bin. The shop told me it was so obsolete that they never would sell it.
I'm gonna do some calling tomorrow & see what I can find out. I would love to use my CM 5052 Spicer but I know it is too long & I don't want to move my transfer rearward. If I did move it I have a RT 613 Fuller but man that little baby is Long!
If the direct trans will interchange maybe I can trade my O/D trans for one.

 

[tobyS]

My friend Matt knows the Allison well. We have rebuilt 2 of the 1545's. Seems there is a really weak point in the tranny's fourth/reverse clutch pack and having the locking torque converter makes that problem worse.

The GM 4L80 has many high performance parts (clutch's and pistons) with people using them in pulling. They say people are putting the 4L80 behind up to 1000 hp. It's "direct" clutch is the same as the Allison's fourth/reverse. While the 2 we have rebuilt use the new seals, we kept the OEM (style) clutch pack and aluminum piston. Next one gets the high performance set with 40% more surface and 25% more pressure.

I'm not trying to sell you on Allison, just to let you know there are some mods that I believe will make it more reliable. On the contrary...I like your OD Spicer and would almost prefer it in my 4x4 because it's an OD.

I hope someone that knows the deuce old and new trans (Spicer) will speak up/reply. Might have to PM Grendel. That would be a trade that would seem a lot of guys would make with you if the word can get to the right people (bobbers).

 

[tobyS]

Take a look at this thread to start on

https://www.steelsoldiers.com/showthread.php?56075-M-35-5-speed-spicer-3053a-swap-to-5-ton-s

Isn't the swap a 3052 for the 3053, or are you intending to use the 5 ton tranny in the deuce?

 

[tobyS]

This thread says the gut of one will go to the guts of the other.

www.steelsoldiers.com/showthread.php?28845-transmissions

"PTO will bolt up fine. For off road it would be nice, the gears are spaced better without the overdrive. Same transmission, different gearsets, will interchange."


And by G;

Spicer 3052, 5th direct: 7.552, 4.182, 2.446, 1.455, 1.000, R 7.364
Spicer 3053A, 5th o.d. : 5.013, 2.776, 1.624, 1.000, 0.787, R 4.888


PTO is the same for both but output rpm is only 0.66%, mounted on a 3052 (if 3053 was 100%).

 

[cattlerepairman]

I am curious...

When I am heavy, I put the transfer into LOW, start off in 2, shift 2-3-4-5, then go into HIGH and shift 4-5. Seems easier on the clutch. Seems to get going quite easily, even when loaded.
The 3052 tranny gives better spacing of the gears but you are effectively neutering your truck to around 40 mph at 2500 rpm, otherwise stock. Try the calculator: http://www.4lo.com/calc/gearratio.php

- 40" tires
- 6.7221 differential ratio
- Transfer case ratio is 1 in high
- .79 ratio for stock 5th on the 3053 vs. 1 on the 3052
Put in 2500 as engine rpm and leave the speed blank.

My 5 cents is that the low range is there for a reason; I'd rather use it than swapping out a tranny and then have a truck that is even slower than stock. Sure, you could put bigger tires on, but you would be trying to fix what you broke in the first place...

Thanks to gringeltaube, here are the gear ratios:

Spicer 3052, 5th direct: 7.552, 4.182, 2.446, 1.455, 1.000, R 7.364
Spicer 3053A, 5th o.d. : 5.013, 2.776, 1.624, 1.000, 0.787, R 4.888

 

[andyh1956]

By looking at the ratio chart you posted it confirms my suspicions... What you gain on top for O/D you lose on the bottom in 1st!
Thanks!
This is a lot like some Fuller transmissions. A 15 speed has the O/D in front & looses on Low whereas a 13 speed has the O/D in the rear & has good reduction in Low!
Funny thing is a few yrs ago I had a residual M35 that I sold the axles & transfer case out of. When the boy came to get it I didn't feel like stripping the truck down & told him just take the whole carcass with you & there was a direct transmission hanging in there! I may try to run him down & see if I can get it back.
I talked to Chris at Memphis Eqpt & he said the two transmissions are the same save the gear differences. He also said they have bunches of the direct transmissions & the parts dept may trade with me.
Keep Ya Posted!