I ahve an '87 with a 6 cyl and 4 spd w/ granny low. I would like to swap it for a later model 5 spd with an O/D.

Any ideas?

I will probably do a clutch change and a rear main seal change. My clutch chatters on takeoff. I just bought this truck and I think the clutch is contaminated with oil.

 

I did the exact opposite of that with my truck because the bellhousing split in half on the zf 5 speed and we had a 4 speed in the back of the shop. You will need all the plumbing for the 5 speed I'm sure.

 

I would like to do the opposite of what you are doing. I'm wanting the four speed with granny low. I have a 5spd with 3.08 rears and would like the granny gear for easing around the orchard. Where are you located?? Maybe we could work something out! Mine is an 89 2WD LWB by the way. I don't know if the driveshaft length would be a problem. I haven't really studied this very much.

 

I am in St. Louis, MO. I am currently using this as my daily driver. It gets 3 times the mileage as my full size van with a 302 (5.0L).

I will need to study on the driveshaft. Could you measure yours? Measure from yoke to yoke. I will do the same for mine. If the measurements are the same, we may just get with a tranny swap. What kind of clutch fork do you have?

 

I don't know..mine is down right now. Be Sat before I can check though. I'm in SW Arkansas so not to far away...haha. I'll check sat and let you know.

 

Probably need to check crossmember location and construction. Maybe someone that has some experience in this will chime in.

 

I swapped a NP435/208 combo in place of the M5OD/1356 in my 88 a few years ago. The oiler slinger had cracked, consequently welding the input shaft to the mainshaft in the transmissin.

I think I used the original crossmember; but I know I swapped the tranny cover in the floor pan, so I didn't have to cut a hole for the t-case shifter. I don't remember if the transmission shifter hole was in the same place or not. The driveshafts were different on my 4WD, not sure about the 2WD.

THe M5OD has a concentric slave cylinder, the NP435 has an external slave. It is easiest to change the hole hydraulic system.

I did not have to change the speedometer gear.

A parts truck is about the cheapest way to do this swap, all the little things you don't think about will nckle and dime you to death at the junkyard. I used an 84 for parts. everything bolted in, no cutting torch or welder needed.

Hope this helps,

Robert

 

Thanks, Robert.

 

Good news, my memory jolted.

So I had to cut my crossmember underneath the transmission and modify it to get the 4 speed to work, so yours will have to be modified.

I had to cut the floor because the shifter for the 4 speed is futher forward then the 1 of the 5 speed.

I did away with all of my hydraulic lines for the transmission because the master cylinder for the 5 speed isn't big enough to pump up the slave cylinder for the 4 speed. So I made a mechanical linkage which is pretty killer if you ask me. You can actually feel when the clutch engages.

The 4 speed and 5 speed are different lengths. I think the 4 speed is shorter than the 5 speed so you will need a shorter drive shaft.

The only parts I had for the 4 speed was the actual 4 speed and the shifter for it. I had to go and get the only NP435 to 351w bellhousing in any junkyard in the state of wisconsin, I made the mechanical clutch using the clutch cam from a mid 70's ford, and tie rods from a snowmobile with heim joints in the ends. I also modified driveshafts so that they were the right length. It was a FULL 3 day process getting it all ready to drive again.