more speed out of my granny tranny

[1972 highboy]

hi all can someone please tell me if there is anyway to get a little more top end out of the compound low trans with out it costing me an arm and my first born? thank you

[guhfluh]

Bigger tires or change rear gear.

[1972hiboy]

portuguese overdrive. when going downhill, place gearshift selector in neutral, enjoy going over 60mph. No purchase necessary, results may vary,

[motzingg]

if you're talking 4x4, changing gears is at least a $1000 commitment, big tires are at least $1k, and some kind of overdrive with adapters is going to push you past $3k easy.

sounds crazy but the cheapest option is probably going to be swapping the trans with a junkyard ZF, $500 with the T-case if you can find one.

[eggman918]

The t cases that come factory behind a ZF are too wide to fit between the frame rails of a Bump,but if you find a 2WD ZF and have a new intermediate shaft made that would probably be the most cost effective option.When i did the cummins 4BT swap in my '68 i went with a 2WD M5ODR2 and added a divorced ford np203 range box to the front of a '77 np205 bolted to the factory dana 24 mounts and ended up with an intermediate shaft that was 6" long between U joint center lines,the trans was longer and the 203 box and adapter were longer but the T case was in the factory location I have over 10K miles on this configuration and am happy with it.To do this it was necessary to move the trans. cross member back and down to keep the drive line angle correct a digital protractor was invaluable they are ~ $65.00 from Enco here is a good source of info on drive line set up from dana/spicer tells you all you need to know http://www2.dana.com/pdf/DSIG-3311.pd.hope this helps you make the correct decision for your needs.
One more thing ZF's come with bell housings that fit either the 429/460 pattern or the 300-6 302/351 v8's the mrodr2's fit the 300,302,351's the M5's are hydraulic clutch and I "think" all the ZF's are as well but I'm not sure.
Steve.

[sykanr0ng]

Bigger tires you could consider HMMWV take-offs they are usually at least 80% tread, they are 16.5, the HMMWV wheels are double beadlocks most people have them re-centered as they have 7" backspace, they are incredibly cheap.

re the ZF5:
They are all hydraulic clutch, the I6/small block is internal, the big block and diesel are external.
The diesel ZF5 looks very similar to the big block ZF5, but is very difficult to use on a gas engine.
There are none for the FE engine, there is one company that has one sentence on their website saying they make one but NO details or price.(You know the saying "If you have to ask you can't afford it")

The Mazda built M5OD is considered by most to be barely adequate for an F150 with a stock 302 and stock tire size.

For some reason this was broken:

http://www2.dana.com/pdf/DSIG-3311.pdf

[Camper Special]

so my big question is WHY would you want more out of 1st gear?
even with the suggestions above how much can you really get?

[dbarker]

dont think you read that right.. he wants more out of the trans, not just one gear.

the granny 1st trans are geared pretty low and we only get 2-4 to get moving. top end is about 70, and at that speed you're humming along with the trans.... probably wants to move it on up to 75-85... without having crazy high revs. So the only REAL solution is a trans swap or an overdrive unit.

[eggman918]

I've herd that the M5odr2 is week from many,but I also know of many running them behind the Cummins 4BT with success I have ~15K miles on mine in a 8,000lb truck much of it pulling a 4,000lb trailer mu motor is producing ~185 hp and 450ft/lbs I have first hand knowledge of one behind a 4BT with twins in a Bump highboy with compound turbos that makes much more HP/TQ than mine with well over 25,000 miles that has run flawlessly.The biggest issue with the M5odr2 is keeping the fluid full or better yet about 1 quart over full.when I did my swap I found a bone yard trans and did a complete overhaul adding a bit more perload to the main shafts Timken bearings and replaced the rubber plugs with brass plugs as that is where the factory units start to leak.I was skeptical of this trans as well at first from what I had read on line but I did more research AND talked to some people with first hand knowledge/experience with it and took a chance.When I got my core home from the bone yard and disassembled it I was impressed with the construction of it internally the case is stout and all the bearing bores in it have steel liners that the case was cast around the gears are all good sized it has an internal pump to circulate oil to the roller bearings between the gears and the shafts,it reminded me of many of the motorcycle transmissions I had worked on as a kid.This is just my but it is from firsthand experience that I speak and not hearsay,mine is still going strong behind a diesel that would humiliate the strong 390-4v it replaced in a very heavy F-250 that I use hard on and off the highway. One more point if you compare the GVWR/CGVWR's of our F-250's with the early '90's F-150's the F150's are heavier.
heres that link again it is worth the read http://www2.dana.com/pdf/J3311-1-DSSP.pdf

[motzingg]

eggman once again dropping serious knowledge... thats pretty cool.

that pdf is great, i'm getting ready to set up my driveshaft next weekend, thanks for posting that!

[motzingg]

while we're on the topic,

what are you using in your M5 for fluid, just regular Dex/Merc 3 ATF or somethin' fancy?

i run gear saver in some of my 2 stroke moto's that call for ATF in the trans. not sure if thats a good idea.

[eggman918]

I've been running ATF but I'm thinking about using International Harvester hydraulic fluid as I got a deal on a 5 gal.pail of it.
That Dana/spicer site has a LOT of good info on it.