I need a Ford man ;-)

[mitch2]

Somebody to help identify gears in a truck. What info is needed and where can I find it?

55mph is top speed at the moment and that is just before redline on the rpm's.

Michele

 

[Limomike]

Is it a column shift? floor shift? Either way.. it is either a 3 speed or 4 speed transmission.

 

[Crowderfarms]

There should be a tag on the differential housing cover. Should contain the gear ratio, such as: 4:10,3:73, etc. Sounds like you've got some seriously low gears.

 

[Aaron]

What kind of truck is it? F-150, Ranger, etc...need some more info. You can look at the tag on the diff cover or on the door panel sticker. :cowboy:

 

[KenB]

Somebody to help identify gears in a truck. What info is needed and where can I find it?

55mph is top speed at the moment and that is just before redline on the rpm's.

Did this just begin? Is it a manual shift, or automatic?

Michele

 

[mitch2]

Here's is what I have:

1986 f250 HD
6.9 diesel
4wd lockouts
automatic
axle: c5
12 bolt pumpkin cover
8 bolt lug patern
full floating rear axle

What does this mean?
Front GAWR 4410
Rear GAWR 5922

This info came off the door sticker

My dad was trying to figure it out and thinks it is 5:?? something gear.

Geared WAY low!

Michele

 

[mitch2]

Somebody to help identify gears in a truck. What info is needed and where can I find it?

55mph is top speed at the moment and that is just before redline on the rpm's.

Did this just begin? Is it a manual shift, or automatic?

Michele

Manual/ column

Been that way since he bought it probably 5 years ago.

 

[EAT BEEF]

4.10 limited slip I belive ,at least c5 was the code for that in the 90's

 

[Aaron]

Axle code is C5, which means it's 4.10 gears with limited slip. In other words, you got to power to haul a*s, but those gears bite away at your fuel efficiency and will make the truck scream at 2000 RPM. You could switch it out for 3.55 gears, which would increase fuel efficiency and keep the rpm's down. Downside would be less power transferred to the wheels. To do so, you would have to pull the back axle shafts out and switch out the gears. To do so, shop would probably charge about $600 in labour. 3.55 gears would cost another $200 easy. :cowboy:

 

[Crowderfarms]

You sure this truck is shifting to 3rd gear? optional/standard gear ratios in 1986 with a 6.9 were 3:54 and 4:10 ratio if I remember correctly.I just sold an 86 F350 4x4 with auto. trans and 4:10's and it went down the road great.

 

[mitch2]

I would think dad would know if the truck were grabbing 3rd gear. But then again, maybe not! I have never personally driven the truck, but the next time I visit, I will give it a spin.

I will report back within a week or two.

Thanks for the reply's!

Michele

 

[cfpinz]

The truck's 22 years old. Good chance somebody could have swapped out the gears in that time. The only way to know for certain is to jerk the cover off and read the number off the big gear or count the number of teeth on each and divide the small number into the big one. I've got a 86 with 4.10s and no od and it will go about 65 or 70 before it blows. But 45 is a lot more comfortable.

How fast do you really need to go?

 

[Mat Man]

Something dont sound right about the gears problem,I would check on motor problems,
air filter, fuel filter,fuel pump,injecters.Is there a chip that might help on that year model.

 

[mitch2]

cfp - Not that it needs to go that fast, but the fuel efficiency is the main reason. That and dad doesn't need to really pull the Mississippi River anywhere.

Other reason to know gears - if it is a 5:?? gears, we can swap with a mud bogger or something in that field with 3:55 and they will pay the change over and give us the new set of gears for no $$ changing hands.

Michele

 

[Crowderfarms]

Blew a Converter out with an air hose.... Right. :lol2:

 

[Earl Thigpen]

In most cases in vehicles that old the ratio in the transmission top gear was 1:1 (no overdrive). So even with a 4.10:1 rear end ratio at 60 MPH the engine would only be spinning about 3000RPM, given a normal tire size. So I don't think the final gear ratio is the cause of the problem. Even with a 5.12:1 final ratio top speed would be much greater than 55MPH

You mention the truck is 4WD. Could the transfer case be stuck in 4 low?

Forget everything I said above. You said the engine was a diesel. Red line on the diesel is 3000 RPM or so? In order to make diesels perform like their gas counterparts they need the right gearing. So with a 4.10:1 final ratio you MUST have some overdrive capability in the transmission. My diesel is very happy with a 3.73 final ratio but with two overdrive gears plus lockup I'm cruising at 80MPH at 2700 RPM. So we're back to the transfer case. Or if the transmission is an overdrive type you're not getting it into OD.

Good luck and keep us posted on what's really wrong.

 

[hopalong]

Blew a Converter out with an air hose.... Right. :lol2:

LOL nailed that one right on the head lol,
And a mechanic replacing a converter and not charging for it YEA RIGHT

 

[cfpinz]

cfp - Not that it needs to go that fast, but the fuel efficiency is the main reason. That and dad doesn't need to really pull the Mississippi River anywhere.

Other reason to know gears - if it is a 5:?? gears, we can swap with a mud bogger or something in that field with 3:55 and they will pay the change over and give us the new set of gears for no $$ changing hands.

Michele

Just a thought: If you don't want to jerk the cover you can jack up the rear end, place the trans/transer case in neutral and rotate the driveshaft. Your truck should have limited slip so place a mark on one rear tire and on the driveshaft. Rotate the driveshaft by hand and count the revolutions needed to make the tires turn over once. If the back tires don't turn together at the same speed leave one on the ground and turn the driveshaft enough to make the airborne tire rotate twice.

I've got an 86 F350 with 4.10s and no od, it avgs 11mpg. Had an 87 with the same motor/trans and 3.55s, it got 16/17mpg doing the same driving. With an automatic in your father's truck I'd expect 13-15 out of it with 3.55s.

 

[mitch2]

Tranny is C6 - 3 speed auto

Talking on the phone right now.... what is the sequence from front to back for 4wd placement?

So far stuck in low is strong possibility.

Shifts into 3rd gear for certain.

2h
4h
neutral
4l

So now he doesn't think that is the problem.

Michele

 

[cfpinz]

Your sequence is correct. If it was in 4L it wouldn't go over 35.