Allison MT643

[@karroome]

I realy appreciate you taking the time to film and show. and the components on these transmissions are HUGE to say the least. thanks alot

[@GaryFerraro]

+karroome Thank you for watching.

[@transservicecambio]

Good morning, I work with this automatic transmission too

[@robertjackson7590]

Hey Gary, If you have 1st and 4th, you tested Reverse which is both of those clutch packs applied together. First clutch is applied in Neutral so if you want to go into Reverse it only has to charge 4th. If you want to go Forward it only has to apply Forward clutch. Both are the smallest clutch packs in this model. If the Governor sticks and holds it in 2nd gear it will not attain Reverse bc the valve body is designed so that if you're in a higher gear than 1st, Reverse can't be attained. For a hydraulic valve body this is very smart.

[@GaryFerraro]

Thanks for the info, didnt know about if the govenor was stuck no reverse, we dont get to many of these units

[@staym925]

I have a question, I have a mt654, that won't shift into 5th, have no issues in reverse and 1-4, buy just won't shift into 5th. It's in a m925 5 ton military truck, with a cummins 855 nhc 250 engine.

[@robertjackson7590]

@@staym925 These transmissions shift by RPM, if you don't have full throttle it can reach enough RPM through gear ratios to get the lower shifts but every time it makes a shift it is more and more up to the engine. With the engine warmed up get someone to go to the throttle pedal and within about 3-5 seconds push it to the floor in Neutral. You go to the throttle lever at the engine gov and see if you get any more RPM out of the engine. Sometimes 50 RPM is all it takes. A Mechanical Gov isn't 100% so after you adjust the slack out of the throttle check No Load RPM, in Neutral again push the throttle and check the tach, There should be 4-5% Droop between No Load and Full Load RPM. So an engine that Full Load pulls to 2100RPM will No Load to around 2350. Check to make sure your Modulator cable isn't adjusted too tight causing the Throttle not to reach WOT. Replace your Modulator and cable anytime you get your shifts one right after the other @ Full Load WOT. Your Electronic governor engines will have 0% Droop.

[@juandediosgarzon9057]

Buenos días me párese muy buen proyecto seguir fomentando este tipo de trabajo de esta series Allison mejores transmisiones A nivel mundial

[@GaryFerraro]

I do not do many allison units

[@realwoodfurniture1628]

Thanks for the info. Have a MT654CR with no reverse. Allison shop spent 2 hours of my $$ and all I got was that the pressure check went fine and that the trans must be bad since that's what the book says. I asked about gov. filter and if they had tested fluid or dropped the pan. They had not so I drove the truck back and going to investigate myself.

[@GaryFerraro]

how does it upshift? all the gear there?

[@realwoodfurniture1628]

All forward. No reverse.

[@realwoodfurniture1628]

I dropped the pan and have a little material in it.

[@Pleasurechest985]

Does anybody drop the pan anymore? 654cr are junk.

[@errolrobinson8851]

Hey..have a mt643 with some noise whenever its in fwd or rev...possible to share a video with you?

[@eudelmaslenly3767]

Well yes, it has a modulator "cable" it was out of adjustment so I did adjust it and it shifts a little better now. The problem is that its not giving me much speed 55mph.

[@Almeshtages3]

Thanks Gary

[@GaryFerraro]

+‫احمد محمد‬‎ Welcome, Thanks for watching

[@markmcguire920]

How do you replace the torque converter studs? Mine are sheared off. No cracks.

[@GaryFerraro]

They may be pressed in, i'm not 100% sure, i don't get many of these

[@markmcguire920]

I hope so.

[@luisalvinojorge3843]

hello good day thanks for your previous help I come with another good question in reality they are 2 my allison 643 when it warms up it takes a little time to couple and apart and on any steep slope I have to accelerate a lot so that the vehicle moves and I force the engine the second is I offer an allison MTB 644 that features has that box excuse me and thank you very much

[@GaryFerraro]

Does it seem like the engine has no power?

[@luisalvinojorge3843]

the engine is a caterpillar 3208 the other strange failure is that after it warms up it goes on and stops and to return to roll the speed is not coupled do not know if it is a converter or a seal that generates leak

[@williamwhitlock2701]

Hi Gary great information on the Allison ... I have a 4 wd 2001 international pulls good for about 10 -20 miles then will stop pulling and if you let it get cool again it does the same process... any ideas? thanks for your time

[@GaryFerraro]

kinda sounds like your filter id clogging up, have you dropped the pan?

[@williamwhitlock2701]

Yes they said that it was good and checked out the governor said it was good to

[@williamwhitlock2701]

Yes they said that it was good and checked out the governor said it was good to

[@GaryFerraro]

when the pan was down, was the pan clean? this is a 540 model?

[@williamwhitlock2701]

thank you Gary for getting back with me. I changed the filter and electric modulator valve and so far so good. it is a mt643 the pan was clean of metal and fibers. I really appreciate the videos they help a lot

[@Pleasurechest985]

A lot of work for a delay cold going into reverse bud. First thing I would have done is pull the Gov and checked the screen in the rear port. Through a main pressure gauge in the side to see what you have. Drop the pan to check for debris. Was the fluid burnt?

[@GaryFerraro]

Dropped the pan, was clean, Honestly didn't see much, even the seals looked ok

[@leohayslett3617]

I need your help I have a bmw x5 2008 and im having a malfunction in transmission signal come up

[@GaryFerraro]

what codes?

[@bertnerny]

Hi Gary,Thanks for the video.I'm looking at a couple F800's. Bothe crewcab 4x4's. One is a 94 with an mt643 and the other apparently has an md3060. I'm wondering what your opinion is on thoee two transmissions. Both are 55,000 miles or less.Chris

[@GaryFerraro]

Chris, The MT643 strong trans and not bad to work on, i honestly have never worked on a MD3060 so im not sure about that unit. Gary

[@robertjackson7590]

You can't go wrong with either, the MD is run by wire(electronics) If you ever have an Output Speed Sensor code replace the sensor and terminals, not just the sensor if it ohms out of spec. Could just be terminals. I would run engine oil in the MT. Whatever you run in your engine will be good.

[@bertnerny]

Thanks! Good info.

[@GaryFerraro]

Thanks for watching

[@arumalingam]

hi..gary..i have a question for you..i'm from malaysia we got about 30 units of mt643's..we got a major problem with trans front seals...its always leaks after overhaul..the convertor flange is manufactured locally..but its the same manufacturer of our allison transmission malaysia...does the breather got something do with it?..by the way great video..just to inform you i'm going to share your video on facebook...if you allow me to...cheers

[@Pleasurechest985]

How do you know it is the main seal? Did you pressure test the converter to see if the two seals are leaking? Converter studs? Hub gasket ?

[@oscarquinto4660]

garry i have a mt 653 but the problem is when you connect the transmission to forward or reverse the engine turns off, and we already check the transmission but we don't see anything wrong. do you have any idea?

[@ginivalriveramarchena7423]

Es la Válvula de lockups ubicada en la bomba de aceite y el otro lugar es el disco dela turbina q esta roto

[@armandrobert9309]

Allo jai un probleme avec 653 pas de reverse jai changer toute les cile

[@greenstar32]

Hi Gary, any idea why my MT 653 has trouble staying in 5th gear? On the highway it is constantly jumping from 4th to 5th to 4th..gear-hunting, and I can't get it to stay in 5th. I keep telling my mechanic friend that I think it's an engine performance problem in that the engine just does not have enough power as it is running now to keep it up at that speed and rpm to keep 5th gear engaged and so it keeps dropping down...but he disagrees with me. He thinks its all transmission. He says he thinks the engine has plenty of power. I'm wondering if this could have anything to do with engine performance. It's in a 1986 IH Cargostar with a DT466

[@GaryFerraro]

I can tell you that a bad running engine will affect the way the transmission works, do you feel you have to step down on the accelerator more than you normally do to get the truck to move, you may be kicking it down or are you steady on the gas and the truck just drops down to 4th?

[@greenstar32]

It's very tough to tell, and that is my debate with the mechanic. I have driven it a lot more than he has though, and thought and thought and thought about this. I feel like it's right at that point where it should shift and stay in 5th...but the truck can just hardly go faster, so it can't decide what gear to be in. I wonder if I can somehow get some help with this somewhere. It's an older DT466. What state are you in, Gary?

[@eudelmaslenly3767]

Hi, guys... I am having trouble figuring why does my AT 545 allision shifts out real quick. The governor number is 461, the thing is I want to know if I put a 462 governor WILL it give more speed? Please I am really need of some help...

[@GaryFerraro]

have you checked the vacuum modualtor?

[@MrAllisonguru]

Eudel Mas Lenly I can help you with that problem. Contact me

[@MrAllisonguru]

Gary Ferraro no vacuum modulator on that unit. It's a 461 which means it's max rpm is probably 26-2800. Its either an electric modulator or cable.

[@luisalvinojorge3843]

Good as this wanted to ask you about a failure of an allison mt 643 since of disarm completely was reviewed and all the seals are good but only applies first and reverse does not make the changes of truth and I do not know that to revise why they changed the governors And I do not know what to do if you can help me I'll thank you

[@GaryFerraro]

Ok, so does it shift? you only have first and reverse gears?

[@luisalvinojorge3843]

Applies reverse and first but does not realize any change and all the components were tested and nothing is not what else to do

[@GaryFerraro]

The govenor gear is good and the modulator too? check vacuum lines

[@luisalvinojorge3843]

If the governor is good as I try the modulator and the vacuum lines thanks

[@GaryFerraro]

Make sure the valve inside the governor moves

[@theidahomegarage8090]

Is the mt654 mechanical as well? I'd like to swap a 545 for the 654.

[@GaryFerraro]

Not sure if you can do that, the 545is like an overgrown THM400 trans, the 643 is much larger in all ways.

[@psicopatalucifer]

cool.!!!

[@GaryFerraro]

+john CR Thanks for watching

[@luisalvinojorge3843]

hi how is this apologize I offer a box allison mt-644 with retarder that box serves me to change a model mt-643 thanks for your help

[@1970brwr]

i know we been having problem with Allison b400 and 731 angle drive trans on transit bus seal wearing out

[@1970brwr]

because trans cooler clogged or had a restriction causing piston seal to harding and cause the same symptoms you are talking about

[@GaryFerraro]

+derek brewer Thanks for the info, on mine i never really saw anything that jumped out at me, i just addressed all areas and all is well. Thanks for watching

[@oneslave3318]

When that old transit trans locks second it does not pump lube. It was not designed for highway use. It will burn seals unless you stop it every 50 miles or so and restart from 1st gear to resupply some lube.

[@СпасБогданов-ь6м]

Interesuvam se ot Allison MT 41

[@GaryFerraro]

? Translation

[@СпасБогданов-ь6м]

Smenixme malkite diskove sabraxme kutiqta problema e ce nqma zadna skoros

[@GaryFerraro]

?????? Tanslation