Extreme Transmission Leak

[bcaddel]

I just returned from Smith Detroit Allison here in Reno. The service desk told me I should try putting a COPPER WASHER on the bolt that goes through the gasket. He felt there was a good chance this would stop leak. If that didn't work he said it would cost about $1,100 to replace both the front and rear gasket.

I am definatelly going to try the copper washer trick, and most likely will let them do the repair instead of taking the drive to Tucson with the leaking transmission. Does anyone think the copper washer has a chance of working?

[circusboy90210]

willing 2 bet you could do it for less than $300 including parts & tools;-) but while you have it out y not rebuild? check out price of master rebuild kit. transmission jack $175 font rear seal probably$20 a piece

[makemineatwostroke]

I will take that bet circusboy the snap ring puller alone is over $400.00 for a Allision.This guy is headed in the right direction by listening to the Allison dealer, but I don't know about the copper washers it may work for him if it leaking out the bolts   

have a great day

[Busted Knuckle]

willing 2 bet you could do it for less than $300 including parts & tools;-) but while you have it out y not rebuild? check out price of master rebuild kit. transmission jack $175 font rear seal probably$20 a piece

Clownboy you have obviously not done much work on buses! First off a $175 tranny jack will fold over and get you killed or hurt for clowning around with such small tools for heavy equipment repairs (pun intended!) And if you ever find a front or rear tranny seal for an Allison transmission feel free to buy all available and make yerself a profit of around 100% or more while still helping someone save $!

I dropped the subject rather than responding on your thread about where& what to look for? (that has been asked and repeatedly answered over and over in the past to have a qualified bus mechanic inspect it with you!  Where you more or less slapped Dallas, Mike, Sammy, Luke, Cole, Tom, Jack, JR, BW, Bruce, Charles, Clifford, Sonny, Arthur, myself and many others (I can't mention them all as I have memory lapses and there are too many! here who do or have made our living working on buses and willingly, and lovingly give our time and advice free here on the board in the FACE! While at the same time asking for our advice! So even though I may get an trouble I urge to learn the difference of working a VW bus and a REAL BUS, before giving advice that can hurt, kill or cost someone mega dollars and much grief because you haven't got a clue as to what your talking about! These are very big units and not your VW or Chevy camaro! An Allison transmission in one of these buses weighs as much as a VW and half as much as a camaro! So if you'll stick to CLOWNING around those of us who are experienced will stick to giving SERIOUS ADVICE! (again pun intended!)
  BK    aka class clown of the MAK board! LOL!

[JimC]

OUCH!BK, how do you really feel?

Jim

[circusboy90210]

willing 2 bet you could do it for less than $300 including parts & tools;-) but while you have it out y not rebuild? check out price of master rebuild kit. transmission jack $175 font rear seal probably$20 a piece

Clownboy you have obviously not done much work on buses! First off a $175 tranny jack will fold over and get you killed or hurt for clowning around with such small tools for heavy equipment repairs (pun intended!) And if you ever find a front or rear tranny seal for an Allison transmission feel free to buy all available and make yerself a profit of around 100% or more while still helping someone save $!

I dropped the subject rather than responding on your thread about where& what to look for? (that has been asked and repeatedly answered over and over in the past to have a qualified bus mechanic inspect it with you!  Where you more or less slapped Dallas, Mike, Sammy, Luke, Cole, Tom, Jack, JR, BW, Bruce, Charles, Clifford, Sonny, Arthur, myself and many others (I can't mention them all as I have memory lapses and there are too many! here who do or have made our living working on buses and willingly, and lovingly give our time and advice free here on the board in the FACE! While at the same time asking for our advice! So even though I may get an trouble I urge to learn the difference of working a VW bus and a REAL BUS, before giving advice that can hurt, kill or cost someone mega dollars and much grief because you haven't got a clue as to what your talking about! These are very big units and not your VW or Chevy camaro! An Allison transmission in one of these buses weighs as much as a VW and half as much as a camaro! So if you'll stick to CLOWNING around those of us who are experienced will stick to giving SERIOUS ADVICE! (again pun intended!)
  BK    aka class clown of the MAK board! LOL!

concepts all the same just different scale of co$t & weights . a unit weighing more does not affect t key concepts. the class clown ends up being the smarter one in the long run though.
however it's not a slap 2 say if I knew typical issues with busses I would not need bus mechanic as that's y I'm here 2become my own expert,thanx
btw a$175tranny jack can lift 4tons so you r not totally correct. howeve we will see, & this is not a competition bta learning experience. In my fields of endeavor even the most seasoned hand can learn from a total greenhorm, & circus life is a micrcosim of society so I got to learn bout most anything there is2 know about because Igot2 go see things that interest me &ask questions directly of top expertsif they werenot allready doing something for ourshow, or just happened 2 b there.(met many famous,rich ,celebrity orotherwise .

[bcaddel]

Well the copper washers didn't work. I cleaned the area up pretty good and now you can see it is just the one gasket leaking, the gasket on the thread side of the bolt so the washers didn't have a chance. Do you think if I have the Allison Transmission people replace this gasket it will solve the problem. There is no fluid leaking anywhere else just the gasket where these two metal surfaces meet. I attached a picture of transmission leak to this email, you may have to click on it to open it.

I was a little concerned that something is causing excess pressure inside the transmission forcing the fluid out but this fluid came out immediatelly after starting the engine, and the dip stick is never forced out of its holder from pressure so maybe it is just the 4 years of sitting idle caused the gasket to dry out. There does not appear to be any cracks in the metal surfaces anywhere near the leak.

The transmission runs perfect when isn't low of fluid. Before I spend the $1,100 to have them replace the gasket I would like to have a warm fuzzy feeling that there is a good chance it may solve the problem.

[makemineatwostroke]

bcaddel; can you see the gasket i can not tell from the photo.some rebuiders used RTV (black) silicone to assemble the transmission which Allision approved but it never worked for us.Me i would drive the bus to Smiths and if the diagnostics confirm it is the gasket, do it most Allision dealers don't get heavy in your pocket till it is a total rebuild of your transmission instead of a exchange.   have a great evening

[circusboy90210]

looked up prices4 this gasket on several allison products $5 even if you only break even fixing it bybuying tools &manual you will neverbb stuck like that again.

[Busted Knuckle]

concepts all the same just different scale of co$t & weights . a unit weighing more does not affect t key concepts. the class clown ends up being the smarter one in the long run though.
however it's not a slap 2 say if I knew typical issues with busses I would not need bus mechanic as that's y I'm here 2become my own expert,thanxbtw a$175tranny jack can lift 4tons so you r not totally correct. howeve we will see, & this is not a competition bta learning experience. In my fields of endeavor even the most seasoned hand can learn from a total greenhorm, & circus life is a micrcosim of society so I got to learn bout most anything there is2 know about because Igot2 go see things that interest me &ask questions directly of top expertsif they werenot allready doing something for ourshow, or just happened 2 b there.(met many famous,rich ,celebrity orotherwise .

Clownboy the  remark I was remarking about was where you don't trust us mechanics ESPECIALLY DIESEL MECHANICS! (most of us bus MECHANICS qualify here !)

And trust me the el'cheapo harbor freight trans jack will fold over side ways under the weight of an Allison! I know this for a fact when one of my mechanics and my silly uncle pulled a HT740 out of a MCI 9 with out pulling the engine together while I was off on a trip! They folded that jack over and almost hurt both of themselves, destroyed the trans pan, and still couldn't get it out from under the bus! BTDT! Sometime you'll learn more by listening to those who know, rather than pretend to know it all while giving bad/false advice!

Also like my Granddaddy (god rest his soul) used to say "ya know sometimes it best to keep yo mouth shut, and let folks think ya a fool. Than to open it and remove all doubt!"

FWIW    BK 

[letz4wheel]

I don't ever think I have seen BK angry before 

[Sojourner]

Bcaddel....I believe you have a missing copper or been reused (a no-no) or damage "O" ring gasket in-between low clutch housing and main transmission housing in the oil pressure passage...there 2 of them next to each other in parallel. See photo with description labeled. It could be unclean surface around the housing's mating surface such as part of old gasket over new one to cause not enough compression to seal to seal well from "O" ring gaskets. It looks like it been tamper with lately and poorly reassembled.

The light green is the passages in the photo. You notice there two pressure taps.

This involves removing tail shaft housing and low clutch housing. Allison mechanic job to repair and reassembled with proper end play.

FWIW

Sojourn for Christ, Gerald

[Sojourner]

To all bus nuts...here a good example why photo is a good thing and save all the rehashing of all sorts of guessing statement. It allmost like being there.

Thank you bcaddel for sharing that photo and a great one too.

FWIW

Sojourn for Christ, Gerald

[pipes]

My 2 cents worth !
                                Years ago I replaced my 4 speed trans with a used 10 speed. It was very grungy on the outside with oil and road grime. I pressure washed it, and then one by one I removed every bolt that entered into and THRU the casing and put shellac gasket goo on the bolt threads and put them back.And painted both trans and engine gray...........
                                              I also did the same to the  8V71 where bolts went into  water or oil galleries
There is NO oil or water stains on engine or trans!!!!............I am thinking this MIGHT stop the leaks on your gasket bolts..........HOPE SO .Ken.......... 05 Eagle

[bcaddel]

Gerald
Thanks very much for your input, your comments seem to be right on track but I am 100% certain the transmission has NOT been tampered with in any way. It was installed in the bus by AZ transmission and engine exchange in Tucson in 1998. It has ran for 12,000 with no issues or leaks. It just suddenly started pouring oil out while driving down the road (1 gal pr hour). I took two bolts out yesterday and put the copper washers on them as recommended by Allison mechanic and cleaned it up to see what would happen. That is when I discovered it was coming out the gasket on the threaded end of the bolt only. Does that change your thoughts any?

My son-in-law is a diesel mechanic (but not a transmission mechanic) and worked for Smith Detroit Allison for 6 years, he  has been a diesel mechanic for the State for the last 10 years. (I have come to appreciate the value of a quality son-in-law over the last 3 months) He has looked at the transmission manuel for the MT 654 and feels he can make the repair properly if it is only the gaskets we need to replace. Do you think that would solve the problem or just open a can of worms and it would have to be reassembled by a allison technician.