mt654 auto on a 6v92ta

[sledhead]

I have been looking for a 5 speed auto for my 6v92ta to replace my ht740 auto I have now . I did have a deal on a ht754 but I could not find the electronics to make it work . So is the mt654 a non elect. transmission and would it be strong enough to handle all that power of the 6v92 ta ddec (350 hp )  I see lots for sale .

thanks  dave

[dinahmoedave]

It is non electric and i think it would be fine in a bus application (motorhome) but how much wieght etc are you pulling and where? ie hills mountains, fla beaches etc. The archives will tell you yes and no but there are sure to be specs for that trans. good luck. And where do you see them for sale? Online or the trader papers?
Also check the specs to see if you are getting a true five speed or a four with a low that sort of thing. I think Trans Diesel of Central fla could help  407-295-1221 or email davidf@transdiesel.net Good luck and let us know what you do.

[luvrbus]

You don't want a 600 series behind a 6v92 they are not rated for enough hp(250) or torque(640) for the 6v92, the 600 uses a # 2 bellhousing or a drop ring and a different flexplate it has the starter ring on the flexplate where the 740 starter ring is on the torque converter and uses a  sae # 1 bell housing  forget the 600 series if I remember the 600 series did not have a close ratio only the deep ratio on a 5 speed

 If you want a close ratio 4 speed just change the planetary gears in the 740 only part you can change on either the 754 or 740  transmission is the 1:1 final 

[Ed Hackenbruch]

The sheet that i have on the MT654CR says it is good up to 300 hp max, and 780 ft. lb. max, and up to 80,000 lbs GVW.  Also says it uses a SAE 1 or 2 flywheel housing.  Size is L  36.23 in., W 19.25 in., H 21.60 in., and weight is 625 lbs.

[sledhead]

I have seen this unit on mid to late 80's in wonderlodge rv's  6v92 ta with 5 speed mt654 .  I have had no problems with my 740 just looking for a 5 speed .   

thanks    dave

[luvrbus]

Still not enough Ed for his 6v92 I never saw 654CR I before saw lots of 654DR came from trash trucks and you can use a SAE 1 bell housing but it requires the drop plate adapter your 5 probably has one mine did both will work since the starter ring is on the flexplate a 740 will not work on a SAE 2 bell housing how ever

Dave the BB had a de tuned 6v92 in that era that is why they were red in color I have changed those over to the silver rating before

[Ed Hackenbruch]

Clifford, i don't have the 654, i have the 644 in my 5, the 644 is 6 in. shorter than the 654.

[skihor]

I have a 5 speed in my 5A. I was told it was a 6?? whatever by an Allison mechanic. I think he said that it was popular in trash trucks. I think he said 654 model. I have what should be a 350 HP 6V92. 9G90 injectors and Turbo set up for the 350 HP. I must have something besides the injector/turbo set up making HP. Advance timing ? maybe. I know that the Allison man couldn't believe how my bus accelerates. My cooling needs are unreal. I have doubled the rads and still have trouble. (everything else is as it should be). Anyway I drive it pedal on the floor whenever possible. Mostly towing a car or trailer. Damn this thing moves... Even @ 10,000' plus I can climb a 5% or 6% grade @ 50 + MPH.We have put over 40K and previous mileage unknown. I was advised not to open the trans up as many parts are unobtainium. Maybe I'm on borowed time but it has worked for us.
Don & Sheila

[luvrbus]

92 series are not A timed with those injectors fwiw,that is a strange setup the 700 series will fit a Mci 5 with a 6v92 the C had a 740 behind the 6v71

[skihor]

92 series are not A timed with those injectors fwiw,that is a strange setup the 700 series will fit a Mci 5 with a 6v92 the C had a 740 behind the 6v71

When I bought it, it had 9200 injectors. It's not low gearing. It tops out about 100 mph. @ 75 I think it's @ 2050 rpm. Governed @ 2350. I'm usually towing approx. 3500# and the bus weighs in @ 10,000# front and 17, 000# rear axle. Judging from the answers on the ratings of the 6?? trans maybe I should be looking for a pre-emptive replacement...

Don & Sheila

[luvrbus]

It's probably a old 60 or 70 that had the overdrive all I can tell you about the 9g90 injectors is the timing is built in the injectors install those in A timed engines they are junk 

The 9200 work with A timed engine your 6v92 was probably around 380 to 400 hp with the 9200 injectors with plenty of smoke

[sledhead]

After looking up the specs on the mt 654 cr

mt 654 cr                 ht  740
 
1st 4.17                  1st 3.69
2nd 2.21                  2nd 2.02
3rd 1.66                   3rd 1.38
4th 1.27                   4th 1.00
5th 1.00

I like the idea of not having the electronics in the trans as I have had no luck finding any for the ht754 trans. Is there a ht 5 speed cr trans. out there with no electronics like the ht 740 ? I have seen a lot of the mt 654cr on the internet for sale , it looks like it was made into the late 1990's    thanks  dave

[TomC]

For the amount of work necessary to convert to the MT654CR, and the fact you'll have to derate the 6V-92TA down to 780lb/ft torque, I'd keep the unbelievably reliable and super strong HT740 (it is the transmission that's used in just about every hot rod Diesel truck). Instead, I'd soup up the 6V-92TA. Jay Leno has a specially prepared (by Valley Detroit Diesel) 6V-92TA DDEC in his Flx that puts out 435hp and 1350lb/ft torque. You'll find out the hard way that the 5spd just isn't going to make that much difference in your speed up the hill (maybe 2-3mph). What gets you up the hill is raw torque. Upping your engine torque from the 1,000lb/ft to 1350lb/ft-that will get you a noticeable increase in up hill performance. Good Luck, TomC

[Bill Gerrie]

Isn't it true that the more HP you get from an engine the shorter the life of it. Something has to give.
Bill

[Boomer]

I don't think Jay owns that bus I think his mechanic does.