| Author |
Message |
Jojo Colina (Du1jec) (209.75.20.72)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 09, 2002 - 8:01 pm: | |
I have acquired an Allison MT-643 which came off a Detroit 8.2. What would I need to install this on an 8v71 and put it in my MCI-5a?
Thanks in advance.
Jojo |
jim (209.240.222.32)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 10, 2002 - 1:12 pm: | |
i recommend not using this transmission.....it was designed to be used with the 8.2's... the 3208 cats....9.0 liter internationals.... it does not have the ability to handle the hp and torque of the 8v71....it was designed for about 100hp less....it would be marginal on a 6v71....however if you could get it to fit, the torque convertor would need to be matched to the 8v71 profile.... |
Tom Caffrey (Pvcces) (12.146.33.229)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 10, 2002 - 11:02 pm: | |
Hi Jojo.
I would think that you would need to readjust all the shift points to match the lower governed speed, as well, if they will adjust down that low.
If the transmission is supposed to shift at 2500, you will need to be going downhill and overspeeding your engine to get the 8V71 up to that speed. When the shift comes, it'll be a lurch like you wouldn't believe.
Tom Caffrey PD4106-2576 |
Gary Carter (12.65.24.173)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 11, 2002 - 5:35 pm: | |
Some versions of the 600 series will work behind the 8V71 with standard timing and N60s injectors. You need to check the serial number and find out what you have. This is a common swap into MCI5s as it is a good fit. Other options is 700 series with a 6V92TA |
Rodger Manecke (Rodger) (67.235.199.57)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 14, 2002 - 2:23 pm: | |
My Prevost Champion S41 (35') has an 8V71 with an MT 644. The MT 644 was installed for a former owner by Dean's Coach in Durham, NC.
It seems to be a good match RPM wise, has at least 35K miles since installation - maybe quite a lot more - and is going strong.
About 25 K miles on the trans fluid which is still clean and red, no metal in pan or filter.
Somewhere I read that Bluebird has used MT644's with 6V92's.
Rodger |
Jim Nelson (65.56.20.208)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 15, 2002 - 9:41 pm: | |
I believe the 8.2l Detroit had a smaller bellhousing than the MCI-spec 8V71's did. There are 2 bellhousing sizes - different enough that a tape measure is all you'd need to tell. The shift points definitely will go low enough - however, you'd need a valve body machine, which requires a visit to a friendly Allison shop. |