[Paccool]

Hmmm, not sure but it may be due to you not having a throttle position sensor. what kind of tranny was behind the 4BT in it's previous life?

Does the tranny shift into OD ok and just won't downshift?

 

[JakeDiesel]

It came out of and Ingersoll Rand Asphault roller.

I shift it into overdrive with a switch I put in the dash.

It downshifts but not as soon as I would like it to.

They has throttle pos. sensor back in 91 on them?

 

[Paccool]

The reason I asked about the TPS is I changed out the TPS with a potentiometer on the dash and mine doesn't want to shift down as fast either. I manually shift it down if I want it to kick in faster. I can control where it shifts up at but it doesn't like the downshift part.

The TPS was mounted on the top of the injection pumps. 91.5 is when the intercooled trucks came out and they had the 518 tranny.

 

[JakeDiesel]

I thought that controlled the OD.

Thats what mine does. Thankyou I will just downshift manually I dont have a problem with that.

Do you think that it not downshifting and it puking the trans fluid can be related?

Have you heard of any type of anti foaming addtives?

 

[Paccool]

Are you sure the tranny has the right dip stick in it? If it is stock, do you know how many pints of fluid you put in it.

If it is foaming, are you sure there is no water in the fluid?

What kind of cooler do you have up front? Does the 4B have the water to fluid cooler on the passenger side of the block?

Where are you taking the tranny temp at? in the hot line going to the cooler or in the pan? If in the pan, I have been told the hot line temps are about 60 degrees higher. I can't say for sure but was told that. My temp gauge is in the pan and I am usually in the 130-160 range I try to keep it below 190 when towing and have Amsoil in it so it doesn't break down as bad when/if it gets hot.

 

[JakeDiesel]

I get my temp coming out of the pan.
I have an air to oil cooler in front of the radaitor. Yes it stock dipstick. There shouldnt be any water in ut. If there was it probably all gone now.

It has an engine oil cooler on the side of the block. cooled by water like the 5.9s

I calls for Dexron II but they don't make that any more and The guy at the parts store showed me the oil that replaces the Dexron II, It says what it replaces in the jug so I use that.

I know the first time that it puked it had too much fluid but not the other times.

 

[dpuckett]

Have you adjusted the bands? There are instructions on that in the FSM.

Keep in mind that the diesel autos wont go into "passing gear" like a gasser will- there just arent enough RPMs to mess with. Mom complained about that when she borrowed my W250 a month ago. I told her it was stock and it was turbo lag.

Daniel

 

[Steve g]

Keep in mind that the "kickdown cable" is more than a kickdown. It controls throttle valve pressure in the trans which will affect shift timing and crispness under all throttle situations. It also boosts line pressure under heavy throttle to increase clutch and band apply pressures. Does the job that vacuum modulaters on Ford and GM did as well as the kickdown function. What speeds are your 1-2 and 2-3 shifts under light throttle pressure? If you're into high gear too soon it will cause increased temps. 190* seems high even on a hot day if no load/hills.Also, unless you have a very large trans cooler you may need the coolant to fluid heat exchange as well to bring temps down.

I'm not sure, but there may also be a corelation between your od setup and your shifting. I had early soft shifts and found my detent cable stuck (also didn't have full pedal travel). Corrected that and shifts were fine as expected, but my overdrive started working properly. Used to hunt and shuttle in and out at about 80kph under light throttle when the tv cable was stuck. After fixing the cable od does not hunt and shifts much better. I was of the opinion that the od system was seperate from the valve body/123 shift, but now I'm not too sure.


Steve g