Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: MT Ted on April 22, 2019, 03:13:30 pm

Title: 92 alison ht746?
Post by: MT Ted on April 22, 2019, 03:13:30 pm
Something Ive wanted to ask you guys for quite awhile now. When I take off from a stop light, empty or towing the trailer. When the transmission shifts from 1st to 2nd, there is a fairly long delay before it actually, what I think locks in? Its almost like it slips? Does yours do this? It goes through all the other gears just fine, both up and down. The oil is clean doesn't smell burnt, new trans filter last year.
Title: Re: 92 alison ht746?
Post by: craneman on April 22, 2019, 03:32:26 pm
You are probably feeling the converter lock up.
Title: Re: 92 alison ht746?
Post by: Mike Leary (RIP) on April 22, 2019, 03:35:58 pm
Could be; my six speed shifts NOW coming off the line.
Title: Re: 92 alison ht746?
Post by: Pierce & Gaylie Stewart on April 22, 2019, 04:54:38 pm
Something Ive wanted to ask you guys for quite awhile now. When I take off from a stop light, empty or towing the trailer. When the transmission shifts from 1st to 2nd, there is a fairly long delay before it actually, what I think locks in? Its almost like it slips? Does yours do this? It goes through all the other gears just fine, both up and down. The oil is clean doesn't smell burnt, new trans filter last year.
The transmission shifts four times as if it were a five speed. Using full throttle, it accelerates fairly slowly in first, shifts into second right at 2130 RPM, continues to accelerate moderately until it makes a fast shift into lock up. Then it's like someone put a big hand behind the coach as it accelerates really well the rest of the way in second followed by another quick shift into third. Fairly big ratio gap here so it takes a couple of seconds to really start accelerating again with another quick shift into fourth at about 57 MPH. Big gap in ratios here so it's frustrating on some grades shifting down and back up. I just leave it in third at 2100 until I reach the top of the grade. The four speed is really lacking compared to the six speed in ratios. First gear is really bad with a 4.xx ratio compared to the six speed's 6.xx ratio. Fourth is a compromise as it's not tall enough for a lower RPM cruise like the six speeds. Top speed is limited to 82 MPH at fuel cutoff (2130 RPM) The mileage suffers a little but still good.

The DDEC II is set for "no smoke" coming off the line in first. The DDEC has to receive a certain boost pressure before it starts adding a lot of fuel. The setting can be changed on DDEC III but not on ours. A resistor can be placed after the sensor so it gets fuel right away but may puff a little smoke, especially at altitude. This is why it's a dog off the line.

All of our shifts are almost instantaneous. No slow shifting or slipping.

Pierce