jerky trani and loose steering

robertglines1 · February 16, 2021, 11:12:37 AM

give me last letter in your serial number and last 4 digits. you can PM me on this page if you feel more comfortable with that. records before 1990 are rare.. Also check on side of steering box and see if it has a jam nut with bolt inside of it (for adjusting play in wheel) Bob

robertglines1 · February 16, 2021, 11:15:23 AM

letter=year of mfg last 4 = unit number might be last 3 that early. I had a 89 was K last 3 were 747 K-747

Tedsoldbus · February 16, 2021, 12:44:42 PM

I'm 64, but happy to have an old guy drive it and tell me, shift points need adjustment and drive it like this, or, suck it up

Tedsoldbus · February 16, 2021, 12:48:51 PM

I am sure i can learn the nuance of driving this, but will see if it can be a bit less jolty. Rita won't want to deal with thwat, and she liked driving the Allegro bus. If I win the lottery, is there another option? Engine is mounted straight, not sideways if that makes a difference.

buswarrior · February 16, 2021, 12:55:31 PM

Don't give up hope until some experienced eyes are cast on it.

If someone else tried messing with it, they could have it all screwed up, just by misadjustment.

For nicest driveability, as noted, you let the tranny do 1-2 with the shifter in 2, and you choose when 3 and 4 happen, which would be at the governor. The 740 is too eager to shift up, when the engine does not have the power to pull, and bang! You get a violent downshift back to a gear that works.

Not a big problem, if someone calmly just demonstrates.

As to an upgrade, it all depends how much room is in there, between the inside edge of the bumper and the differential.

Does this have a drop box, driveshaft heading "over the shoulder" or driveshaft straight into diff?

Happy coaching!
Buswarrior

Tedsoldbus · February 16, 2021, 01:11:46 PM

Thanks for the encouragement. Not in a despair state. Just need to know if this is normal or can be tweeked. Hard to tell without an experienced hand on it. I was getting the hang of what you described as I got it home from the 200 mile trip of picking it up from seller, but pretty much parked now until I get the steering addressed. Too spooky at hwy speeds to want to go anywhere until I am going where that can get adjusted. Still very glad to have found a 35 foot Prevost. Didn't know they made them!!
I am very worried about the engine. It is a 6V92 Turbo....and it hasn't leaked oil. Should I just sell it now???
Best regards, stay warm.
Ted

robertglines1 · February 16, 2021, 01:27:10 PM

general location so we can suggest someone close by?

Tedsoldbus · February 16, 2021, 02:00:37 PM

generally 103 Patrick Point, Blairsville Ga 30512 phone 706-994-07038. Retired military so usually home. Covid number 2 tomorrow but otherwise free.
Thanks
Ted Lammot

Tedsoldbus · February 16, 2021, 02:01:11 PM

woops. Phone is 706-994-7038

Tedsoldbus · February 16, 2021, 02:01:38 PM

woops. Phone is 706-994-7038

luvrbus · February 16, 2021, 02:21:09 PM

If you can tell us what RPM the 740 is shifting into what gear we can tell you if the shift points are off, I doubt the shift points are off

RJ · February 16, 2021, 03:36:36 PM

Quote from: luvrbus on February 16, 2021, 02:21:09 PM
If you can tell us what RPM the 740 is shifting into what gear we can tell you if the shift points are off, I doubt the shift points are off

Clifford -

Didn't Allison make a "soft-shift" kit for the HT-740s and HT-754s? Different springs in the valve bodies or something like that?

RJ · February 16, 2021, 03:59:51 PM

Quote from: Tedsoldbus on February 16, 2021, 02:00:37 PM
generally 103 Patrick Point, Blairsville Ga 30512 phone 706-994-07038. Retired military so usually home. Covid number 2 tomorrow but otherwise free.
Thanks Ted Lammot

Ted -

IIRC, the shift pattern for the HT-740, when it's in 4th (D) is as follows:

1U > 2U > 2L > 3L > 4L

U = Unlocked torque converter
L = Locked torque converter

When the torque converter locks up, it feels like another shift, which is why some folk get confused thinking that it's a five-speed.

The herky-jerky's often take place when you're rolling at a speed and the transmission can't figure out if it should be in 2U, 2L or 3L. Stepping on the throttle often exacerbates this indecision. Driving it like a manual box, especially around town, will quiet a lot of the confusion.

Another tip: Take the bus out on a quiet back road and, from a dead stop, transmission in 1st, start rolling and run the engine right up to the governor and hold it. Once there, make note of the road speed. Now shift to 2nd and repeat, then once more again for 3rd. Head back home, and borrow Rita's white nail polish. Using the noted maximum speeds in each of the lower gears, put a white dot of polish at each of those numbers. Voila - a quick reference that will help you know a) when to downshift, and b) which gear you should be running in when the needle's between the dots.

The Allegro's transmission was electronically controlled - the HT is strictly old-school dead reliable mechanical. Big difference.

One last point: Take a couple minutes to edit your profile to include your bus year/make/model and powertrain combination, plus your home base city/state in your signature line, similar to mine below. That will also help us help you in finding parts, service, and potentially, neighboring busnuts!

FWIW & HTH. . .

chessie4905 · February 16, 2021, 04:32:27 PM

I believe they did mention the soft shift kit here and on BNO. Unfortunately most likely not been available for years.

Tedsoldbus · February 16, 2021, 06:51:58 PM

Thanks to all and I will print RJ advice. So good news is it probably won't cost me big bucks because it is not broken. I will learn how to help it decide when to shift. Bad news is Rita will only want to drive it on the highway in Kansas. She might also kill me for deciding to keep it and blame it on Covid. So if you see a 35 foot Prevost for sale in N Georgia, you will know.
Thanks again gents
Ted