PLZ help tranny trouble!!!!

[cobra1015]

Alright my tranny was messed up because it would not shift into 1. I sent it back to the dealer and he said it was the shifter. He is going to replace the shifter but now I'm still stuck with another problem. When I am in D and in third gear going 45 my RPM's are at 2k. Now to me that seemed high and then I talked to a few other people and they confirmed it. I was told that when I am at 60 I should be doing 2k not 45. The dealer denies anything being wrong and denies that I should be doing 60 at 2k. I have no idea what the hell could be makin it rev high at such a low RPM. Any ideas?? Also I get horrible gas mileage. I get 180 miles to the tank going 75 on cruise control. Most people get 280-300 on the highway and 180 in city. Its gonna get a tune up this week but I cant see it gaining 100 miles to the tank from just a tune up. Any idea what else it could be? Thanks for any help. Lata Jay

 

[85 Coupe 5.0]

Is it an all stock car?

Sounds to me like it has a set of gears out back. Do you feel all 4 shifts?
If it's hitting all the gears it has to be one of two things.

1. There are gears installed.
2. There are smaller than factory tires installed.

By the way, what kind/year of car are we talking here?

 

[cobra1015]

Is it an all stock car?

Sounds to me like it has a set of gears out back. Do you feel all 4 shifts?
If it's hitting all the gears it has to be one of two things.

1. There are gears installed.
2. There are smaller than factory tires installed.

By the way, what kind/year of car are we talking here?

Oh yea year and make would help huh. It is an 89 GT auto. I feel all 3 gears then when Im told it should be going 60 at 2k Im only doing 45 at 2k. In a normal situation I would shift into OD going 60 but in my case I have to shift into OD going 45 and it is a big pain in the ass. As far as the gears I have no idea. The dealer said it was stock except for the flows, and the rims are not stock they are a set of cheapo chrome rims and they are 15's. I dont know the stock tire size. How the hell could I find out whether or not they are aftermarket gears or not without rippin the rear end apart? With even a set of 4 10's I still dont see how I have to shift up to OD going 45 not 60. Well thats all I know any idea now??

 

[85 Coupe 5.0]

15's are stock in the 1989 model year. The switch to 16's didn't happen untill 90' i believe. I have drove an AOD equiped car before, and the 4th, or OD, usually kicks in really low, like around 40 to 45 MPH or so. But on the highway you should see about 2k or so in OD. I'm almost certain that the dealer didn't check to see if the rearend gears have been swapped out. Factory gears in a auto-equipped car were usually 3.27's, Although i have seen some with 2.73's. There are 4 ways to see what gear you have.

1. Jack the car up and manually count the driveshaft/tire revolutions.

1. Jack up and support the rear of the vehicle.
2. put the transmission in neutral, and disenguage the e-brake.
3. grab a friend, you will need two people to do it accurately this way.
4. mark the driveshaft back by where it bolts to the differential, just draw a short line on the driveshaft, going straight with the driveshaft.
5. Mark the tire, preferrably at the 12, 3, 6, or 9 o'clock position.
6. tell your friend to SLOWLY rotate the tire forward or backward untill they turn it one complete revolution, as they are doing this count how many times the driveshaft turns.
7. make sure both back wheels are turning the same direction, if the other tire spins the opposite way you friend is spinning his, discontinue this test, it will be inaccurate. You have a defective limited slip clutch packs in your rearend or you have an open differential and you will have to determine the ratio by running the tag on the differential or the one on the driver side door.
8. write down how many times the driveshaft turns.
9. say your driveshaft turned 3 and roughly 1/4 turns, turn that into a decimal, 3.25. since 3.25 isn't a ratio that is offered, you most likely have 3.27's, a common gear.

2. Crawl underneath the car and write down all the numbers on the differential tag.

1. get under the car and write down the numbers on the differential tag, it's held on to the differential by one of the cover bolts.
2. do a search on stangnet, or the internet in general about decodeing the numbers.

3. Run the axle code on the options sticker located on the driver side door sill.

1. Open up your driver side door, on the options tag there will be a box that has the letters AX on it. This is your axle code.
2. do a search on stangnet for the decodeing information.

4. Pull the differential cover off and count the teeth on each gear.

1. jack up and support the car.
2. pull the differential cover off.
3. count the number of teeth on the ring (big) gear.
4. count the number of teeth on the pinion (small) gear.
5. divide the number of teeth on the ring gear by the number of teeth on the small gear.

two ideas can potentially be misleading though, what if the door has been changed? What if the axle tag is missing?

The only sure way is to jack up the car and count it manually, or remove the cover and count manually.

My friggin fingers are tired from typing now......

 

[85 Coupe 5.0]

by the way your car has the 8.8 inch Trac-Loc rearend, they are factory equipment on all 5.0L equipped Mustangs from 1986 and up. This will help you on your search for axle codes.

 

[cobra1015]

by the way your car has the 8.8 inch Trac-Loc rearend, they are factory equipment on all 5.0L equipped Mustangs from 1986 and up. This will help you on your search for axle codes.

Lol I bet your fingers were tired. Thanks for all the info by the way. Im probably just gonna jack it up and cound the drive shaft revolutions.

As fat as the OD yea I know if I have it in OD it will shift into it at about 45 but I'm sayin that when Im in D and the car cant go any higher then 3rd I was told I should be going 60 (in D in 3rd gear) goind 2k RPM. In my case im doing 45 (In D in 3rd gear) at 2k RPM. I just didnt understand how even a set of gears who make the car have to be shifted into OD 15 MPH earlier. Thanks for all the info I really appreciate it. Jay

 

[shawn13]

I dont know if this will help but my bronco has 4 10s at 65 im doing a hair over 4 grand and no the front axels not loked in

 

[cobra1015]

I dont know if this will help but my bronco has 4 10s at 65 im doing a hair over 4 grand and no the front axels not loked in

Damn I assume that is in D not OD. I was told by another stang owner that he goes 60 at 2k in D. I have never did it myself considerin my car does 45 at 2k in D and my only other car was a 99 cobra lol. Anyone else out their got an auto that can confirm I should be doing 60 at 2k in D??

 

[ninety15.0]

Im pretty sure that the stock gear for an 89 auto was 2.73. that is a very low gear and i would say that 60@ 2k sounds just about right for third gear. You must have a different set of gears in there, becuase 2k@45 sounds rediculous. Jack the car up and count the drive shaft revolutions. Also just because u have 15" tires and the stock rims were 15" doesnt mean that the Outside diameter of the tire isnt different. Read all three numbers off the side of the tire and then compare that with the stock daimeter. it should be like 225/60/15 or something like that. good luck man

 

[cobra1015]

Im pretty sure that the stock gear for an 89 auto was 2.73. that is a very low gear and i would say that 60@ 2k sounds just about right for third gear. You must have a different set of gears in there, becuase 2k@45 sounds rediculous. Jack the car up and count the drive shaft revolutions. Also just because u have 15" tires and the stock rims were 15" doesnt mean that the Outside diameter of the tire isnt different. Read all three numbers off the side of the tire and then compare that with the stock daimeter. it should be like 225/60/15 or something like that. good luck man

Well if it isnt gears what the hell else would make the tranny rev that high?

 

[strtracer442]

With stock size tires(225/50/15) and a 3.08 gear, your car will be at 44.6 MPH at 2000rpm. If you have 2.73 gears, your speed will be 57mph. I think, but am not sure, that 3.08 was an optional gear on automatic equipped cars.

 

[Mustang5L5]

with 3.73's I do 2000RPM in D at 45MPH. Sounds like you got 3.73's to me.

I think it's perfectactually since most of my driving is on roads that have speed limits of 35-45MPH. I keep the shifter in D and that puts me around 1800-2000RPM right when the engine starts making some good torque. If i need to accelerate, i just roll on the gas and the power is there. It takes less effort to accelerate the car at this RPM

with 2.73's, you would seriously be doing like 1200-1500RPM at 45MPH and if you roll on the gas, it will be sluggish since you are low in the powerband.

I can shift into OD at 45MPH if i want, but i prefer to ride it out to 3000RPM which puts me at 60-65MPH. I only shift into OD when i go abouve 3000RPM, which is above 65MPH. I usually will cruise 10-15 miles at a time on the highway at 3000RPM in D and never had a prob (other than gas milage) the car is more responsive to rolling on the gas to pass cars and such plus i like the exhaust tone at 3000RPM!

When i drive 5-spd, i regularly drive around in a certain gear at 3000-4000RPM. I don't see why revving out is so taboo in automatic cars.

BTW, i get 180 miles to the tank, mostly city driving.

 

[cobra1015]

with 3.73's I do 2000RPM in D at 45MPH. Sounds like you got 3.73's to me.

I think it's perfectactually since most of my driving is on roads that have speed limits of 35-45MPH. I keep the shifter in D and that puts me around 1800-2000RPM right when the engine starts making some good torque. If i need to accelerate, i just roll on the gas and the power is there. It takes less effort to accelerate the car at this RPM

with 2.73's, you would seriously be doing like 1200-1500RPM at 45MPH and if you roll on the gas, it will be sluggish since you are low in the powerband.

I can shift into OD at 45MPH if i want, but i prefer to ride it out to 3000RPM which puts me at 60-65MPH. I only shift into OD when i go abouve 3000RPM, which is above 65MPH. I usually will cruise 10-15 miles at a time on the highway at 3000RPM in D and never had a prob (other than gas milage) the car is more responsive to rolling on the gas to pass cars and such plus i like the exhaust tone at 3000RPM!

When i drive 5-spd, i regularly drive around in a certain gear at 3000-4000RPM. I don't see why revving out is so taboo in automatic cars.

BTW, i get 180 miles to the tank, mostly city driving.

You again lol. Thanks for the info bro. I guess now all I have to do is work on my 180 to the tank all highway drivin at 75 problem. A tune up better fix this bitch or Im gonna go broke!