Bus Conversions dot Com Bulletin Board
September 19, 2014, 10:58:09 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If you had an E-Mag Subscription: By clicking on any ad, a hotlink takes you directly to the advertiser’s website.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: 1 2 [3]   Go Down
  Print  
Author Topic: jake brakes on a 8v71 what 2 look for  (Read 4068 times)
DrivingMissLazy
Hero Member
*****
Offline Offline

Posts: 2634




Ignore
« Reply #30 on: July 13, 2007, 06:46:12 AM »

Tom, based on that would you then feel seven shifts (for a 740) if everything was working properly?
I never felt more than three.

And was there ever something like a 740-HD? I got charged for that when I had my 6V92 upgraded to an 8V92. The shop in Tucson (Arizona Transmission & Engine exchange?) stated that I had to have the heavier duty tranny. As i recall it cost me a few thousand dollars extra above th original quoted price.

Thanks again for all your valuable information and the time it takes to answer all the questions you do.

Richard

The only time Allisons will lock up in first is if the shifter is in 1st.  If it is in 2-6th, it will start in 1st converter, go to 2nd converter, then 2nd lockup up to top gear.  This applies to HT740, HT754, HT755, HD4060, B500.  The MT640, MT643, locked up in 3rd. There were some derivations to this, but only on truck Allisons, like the HT750DR that had a real granny low and would normally start in 2nd.  Then it would lock up in 3rd. (they had a programming that would have each gear go from converter to lockup, so a four speed would be 1C-1L-2C-2L-3C-3L-4C-4L.  Kept the engines more wound up, but worse on mileage).  Good Luck, TomC
Logged

Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride
TomC
Hero Member
*****
Offline Offline

Posts: 6783





Ignore
« Reply #31 on: July 13, 2007, 08:46:05 AM »

The 4 speed that had the 7 converter and lockups was only for a truck.  On a 4 spd you should feel 4 shifts-one being the converter lockup and then the 3 gear shifts.
The only "heavy duty" HT740 I know of was the HT748 that was designed for transit buses.  It had a more robust torque converter with hardened input shaft to take the hundreds of starts and stops per day.  The normal HT740 had a factory rating that easily could take the power of the 8V-92TA-I know this since this was an option when I ordered my first truck in '79 with the 8V-92TA ($8,700 extra said I got the 13 spd instead-but always pined for the Allison).  Hate to say it about the price you paid for the "heavy duty version"..... Good Luck, TomC
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
DrivingMissLazy
Hero Member
*****
Offline Offline

Posts: 2634




Ignore
« Reply #32 on: July 13, 2007, 10:13:18 AM »

Tom, then if I understand correctly my 740 would start out in first, it then would lock up at about 15 for the first shift I felt, then on to second, third and fourth,  for the four shifts I felt.

Regarding the work I had done in Tucson, it was before even the internet and of course no bus boards or anyone to ask questions of. I took it in with an initial estimate of $8,000 to change the engine. It cost me over $25,000 to get it out of there. Boy, what a bunch of crooks.
Richard


The 4 speed that had the 7 converter and lockups was only for a truck.  On a 4 spd you should feel 4 shifts-one being the converter lockup and then the 3 gear shifts.
The only "heavy duty" HT740 I know of was the HT748 that was designed for transit buses.  It had a more robust torque converter with hardened input shaft to take the hundreds of starts and stops per day.  The normal HT740 had a factory rating that easily could take the power of the 8V-92TA-I know this since this was an option when I ordered my first truck in '79 with the 8V-92TA ($8,700 extra said I got the 13 spd instead-but always pined for the Allison).  Hate to say it about the price you paid for the "heavy duty version"..... Good Luck, TomC
Logged

Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride
TomC
Hero Member
*****
Offline Offline

Posts: 6783





Ignore
« Reply #33 on: July 13, 2007, 10:57:23 PM »

All Allisons, including your 740, start in first converter, then shift to second converter, then into second lockup, third lockup, fourth lockup.  The only time you can get lockup in first is by pulling the shift selector down into 1st.  Good Luck, TomC
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
DrivingMissLazy
Hero Member
*****
Offline Offline

Posts: 2634




Ignore
« Reply #34 on: July 14, 2007, 06:10:54 AM »

OK, thanks Tom. I have always wondered what the shift pattern really is.
Richard

All Allisons, including your 740, start in first converter, then shift to second converter, then into second lockup, third lockup, fourth lockup.  The only time you can get lockup in first is by pulling the shift selector down into 1st.  Good Luck, TomC
Logged

Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride
johnjem
http://photobucket.com/johnsgmc4905
Sr. Member
****
Offline Offline

Posts: 266


1970 gmc 4905


WWW

Ignore
« Reply #35 on: July 18, 2007, 05:33:51 PM »

wow 701 veiws  guess it is a good subject 2 talk about!
Logged

Never stop thinking,it"s what keeps us going till tomorrow
http://photobucket.com/johnsgmc4905
johnjem
http://photobucket.com/johnsgmc4905
Sr. Member
****
Offline Offline

Posts: 266


1970 gmc 4905


WWW

Ignore
« Reply #36 on: February 10, 2009, 12:11:26 PM »

hi
Logged

Never stop thinking,it"s what keeps us going till tomorrow
http://photobucket.com/johnsgmc4905
JohnEd
Hero Member
*****
Offline Offline

Posts: 4571




Ignore
« Reply #37 on: February 10, 2009, 02:45:24 PM »

JohnJem,

Hi back atcha.  It was a great post, really.

There is something missing here, though.  There was a post, including pics and detailed instructions, relating to "forcing" the trans to "stay in lock-up" even below 15 MPH.  This would seem to allow the Knut that was picking his way down a really winding steep hill the ability to keep his Jake engaged.  It involved putting in a copper hyd line and a couple fittings.  It got rave reviews at the time.  I hope that data gets added to this as it would make an already outstanding thread even better.

Thanks for the memories,

John
Logged

"An uneducated vote is a treasonous act more damaging than any treachery of the battlefield.
The price of apathy towards public affairs is to be ruled by evil men." Plato
“We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light.”
—Pla
Brian Diehl
Hero Member
*****
Offline Offline

Posts: 984




Ignore
« Reply #38 on: February 10, 2009, 07:12:47 PM »

John,

Here is my information on what I did when I had an Allison in my bus:

http://home.earthlink.net/~diehls0792/HT754TorqueConverterLockup.html

It worked awesome!

Of course, I now have an Eaton Autoshift and can keep it in any gear I want.  The above allowed me to accomplish the same with the automatic.
Logged
Barn Owl
Roanoke, VA
Hero Member
*****
Offline Offline

Posts: 2047


PD4106-1063 "Wheezy Bus"




Ignore
« Reply #39 on: February 10, 2009, 09:51:10 PM »

Any reason that wouldn't work on a V730?
Logged

L. Christley - W3EYE Amateur Extra
Blue Ridge Mountains, S.W. Virginia
It’s the education gained, and the ability to apply, and share, what we learn.
Have fun, be great, that way you have Great Fun!
JohnEd
Hero Member
*****
Offline Offline

Posts: 4571




Ignore
« Reply #40 on: February 10, 2009, 10:38:11 PM »

Brian,

That is the mod I was referring to and everyone else thought it was a SUPER good mod.  I first saw it posted by another Knut cause I remember the pic of the copper tube was from directly under it and it traveled diagonally across the pic.  Maybe you invented it first!!!!!  No matter, it is an idea whose time has come.

Thank you for sharing that,

John
Logged

"An uneducated vote is a treasonous act more damaging than any treachery of the battlefield.
The price of apathy towards public affairs is to be ruled by evil men." Plato
“We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light.”
—Pla
Pages: 1 2 [3]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!