Allison Transmission Questions

[beaver123456]

Re: Allison Transmission Questions

also how to change the oil in the trans and what kinda fliuds ????? im going out for a first trip this weekend hope allgoes good ! :laugh:

 

[BigHartz]

RE: Allison Transmission Questions

I have a 1995 Spartan 5.9L Cummins Allison 6-spd pusher. My problem is rough up shifts. It bucks as if the engine was stalling then shifts hard into the next higher gear. Test driving it yesterday I noticed that the tach would actually drop from 2000rpm to 1000rpm a couple times then shift to the next higher gear at about 1500rpm. After several of these shifts I believe I actually saw the shift indicator go from 1st to 3rd than to 2nd. It will shift this way when up shifting through most all the gears. I noted also that the down shifts are some times very hard and abrupt. When in 6th the converter lockup works correctly and trans will downshift on grades properly. What might be going on? Is there a way I can get the trouble codes without a scanner? Thanks Dave Har

 

[BigHartz]

Re: Allison Transmission Questions

After some Googling I now have the trouble code it is D1 22 14 (Engine Speed Sensor). I'm going to follow that up today (9-29-08). I drove the rig yesterday and I may be wrong about the shifting from 1st to 3rd. It just stalls or hesitates then shifts abruptly into the next higher gear!

 

[BigHartz]

Re: Allison Transmission Questions

It's great I fixed the problem with the rash, hard and abrupt shifts. I found on the front of the Allison Transmission bellhousing adjacent to the torque converter a Engine Speed Sensor. It checked 300 ohms and I know they very seldom fail. I had an erasable code (D1 22 14) for that sensor until I found today (9-29-08 3PM MST) that the wires had pulled out of the plug probably from ice hanging from it and someone re-installed them backwards and they were not reaching all the way into the plug and touching the sensor terminals. I turned them around inserted them all the way into the plug and erased the code stored in the TCU and now the transmission shifts perfectlly. Thanks for all the input fellas. I'M ON THE ROAD AGAIN BigHartz

 

[LEN]

Re: Allison Transmission Questions

Thanks for coming back with what you have found.
So many times people don't report back when they receive no response, It's not that we are not interested it is that we don't have a comment or any help.

LEN

 

[Skeeter1956]

Re: Allison Transmission Questions

well how about me i have an older one 1988 does it have a speed sensor?????

 

[LEN]

Re: Allison Transmission Questions

I would think that you do as this is what the trans uses for shift points up and down.

LEN

 

[dbarton291]

Re: Allison Transmission Questions

Beaver, an 88 with a Cat 3208 probably has an MT series transmission in it. The vehicle most likely has a mechanical modulator that must be adjusted properly for the best shift quality. You need to get the little Mechanics Tips booklet. It has the adjustment procedure in it.

Keep in mind the MT will never have the super smooth shift quality of the world transmission.

As for oil, Allison TranSynd is the best fluid for a heavy duty automatic Allison knows to provide. It's synthetic, and it's expensive but good. The original recommendation for the MT was Dexron, but now the only Dexron that's available now is Dexron VI. I don't know if all the seals in the MT would be compatible with Dex VI. One alternative would be to put Mobil 1 synthetic in it.

For a time, Allison approved the use of C4 engine oils. These will work, but they aren't the best because sometimes the C4s were engineered for the additive packages to work properly when seeing the kind of temperatures around the engine cylinders. The transmission doesn't get that hot.

Remember to change the filter in the pan, use a new pan gasket and torque the pan bolts properly.

You should also check to see if there's an external spin on filter in the transmission cooler circuit. Most of these filters were in the from cooler line, but some ended up in the to cooler line. Change this filter, also.

 

[dbarton291]

Re: Allison Transmission Questions

Skeeter, a 1988 will not have any speed sensors unless it's an ATEC controlled transmission. On the ATEC transmissions, they did not have an engine speed sensor, only an output speed sensor on the rear cover.

With the introduction of the world transmission in 1991, that's when they started using input, turbine and output speed sensors. Those also have adaptive controls to fine tune the shift quality. The turbine speed sensor is internal on the MD and external on the HD.

If you see a selector cable on the transmission, it's hydraulically controlled. If you see a big aluminum Deutsch connector on the side and no selector cable, it's ATEC. The ATEC transmissions also used a throttle position sensor when they were behind a mechanically controlled engine. If the engine was DDEC, or some other electronic engine, it may be getting its throttle signal from a TECL transmission to engine communication link, which is supposed to be a twisted pair of wires between the engine computer and the transmission computer.

Another way to tell if you've got ATEC or not is to look at the transmission model number on the name plate at the right rear of the trans. The ATEC transmissions were MT648, HT741, HT748, HT755. The hydraulic ones were MT643, MT647, HT740, HT747.

 

[dbarton291]

Re: Allison Transmission Questions

Good catch BigHartz! A little common sense goes a long way.

 

[dbarton291]

RE: Allison Transmission Questions

Ernest55, that's a toughie. Could be a lot of things. I would start with cleaning the connector at the transmission.

I've been out of the country for a while and haven't been around. Maybe allisonman will drop in and offer some of his wisdom.

 

[Skeeter1956]

Re: Allison Transmission Questions

so i will look for a dealer that can look at it do you know of aany in western pa ??? i was looking for one .. also if i drive it manuley it works good ,its just the last shift to high at 55 that sucks it want to go back and forth from high to 3 in the 45 -55 range 1988 3208 cat- beaver- high tech- clasic edition=== first drive this week , wish me some luck ill need it :laugh:

 

[dbarton291]

Re: Allison Transmission Questions

Skeeter: Go to www.allisontransmission.com They have a service locater there that lists all the authorized Allison dealer and distributor locations. If you have an MT, look for the locations that are authorized to work on the MT.

 

[dbarton291]

Re: Allison Transmission Questions

Skeeter: Go to www.allisontransmission.com They have a service locater there that lists all the authorized Allison dealer and distributor locations. If you have an MT, look for the locations that are authorized to work on the MT.

 

[AC7880]

RE: Allison Transmission Questions

I have a Allison 3060 6 speed transmission on a 94 Bluebird BMC motorhome rear pusher with Spartan Chassis hooked to a Cummins 8.3 300 HP.

It is leaking (seeping) fluid from the dipstick tube into the trans case, and the electrical harness cover at the front end (front of coach end) of the trans. I understand there are O-rings on the dipstick into the trans, and under the electrical plug cover (where the wiring harness goes into the trans).

I am mechanically inclined. Is this a owner do-able fix, or does it need a pro? Will I need to drain all the trans first (is there fluid above these items)? How many quarts or gallons of trans fluid are in there? Do I need to purchase o-rings from allison, or can I just pull them, then match them up for size at a auto parts house? I'm in Albuquerque NM and we have a stewart-stevenson authorized allison shop in town.

Thanks for any advice,
Dan

 

[dbarton291]

RE: Allison Transmission Questions

AC7880 - 10/11/2008 8:53 PM

I have a Allison 3060 6 speed transmission on a 94 Bluebird BMC motorhome rear pusher with Spartan Chassis hooked to a Cummins 8.3 300 HP.

It is leaking (seeping) fluid from the dipstick tube into the trans case, and the electrical harness cover at the front end (front of coach end) of the trans. I understand there are O-rings on the dipstick into the trans, and under the electrical plug cover (where the wiring harness goes into the trans).

I am mechanically inclined. Is this a owner do-able fix, or does it need a pro? Will I need to drain all the trans first (is there fluid above these items)? How many quarts or gallons of trans fluid are in there? Do I need to purchase o-rings from allison, or can I just pull them, then match them up for size at a auto parts house? I'm in Albuquerque NM and we have a stewart-stevenson authorized allison shop in town.

Thanks for any advice,
Dan

You will need to drain fluid to do either one. The dipstick tube to the case seal is a seal. It is not an O-ring. The dipstick will be retained by at least the self tapping screw on the main case and it just lifts out. The dipstick seal usually comes out with just some finger action.

The O-ring on the main connector to the case is a thick viton one, not something normally found in an auto parts store. To get the main connector out, you have to drop the whole control module. Most owners don't tackle that themselves. I am familiar with S&S. They are a very large distributor.

 

[headhoodlifter]

RE: Allison Transmission Questions

Short cut to change dipstick seal...start engine leave transmission in neutral, (block wheels set brakes and all the saftey stuff) then remove dipstick assembly as previous post and change seal. No mess No refill as oil level is below seal area while running.

 

[fatshot]

RE: Allison Transmission Questions

Hello Allison Man ---

I am considering purchasing a 1993 Country Coach Magna. It has been owned by a racing promoter, and the 8.3 CTA has been tweaked to produce a little over 400 hp. Will the Allison 3060 5-speed in this coach withstand the increased hp & torque? If not, I don't want to touch it. Thanks.

 

[AC7880]

Re: Allison Transmission Questions

I cant answer if it will hold up, but the 3060 is a 6 speed not a 5 speed. 5 and 6 are both overdrive gears.

 

[fatshot]

Re: Allison Transmission Questions

The 3060 can be programmed for either 5 or 6-speed operation. In the case of this coach, with the Cummins 6CTA8.3, it was only programmed for 5 speeds due to engine size and rear axle ratio. Thanks for the advice, though.