4 speed to 5 speed swap

[Ncgomez65]

I have an 86 6.9 4x4 f250 ext cab long bed with a 4 speed tranny. I want to swap in the 5 speed tranny from the 87. How hard is that going to be and what, if any changes will need to be done. Will that also be cheaper then buying an overdrive unit.

 

[DragRag]

I have done that swap. Nothing to do really besides change the clutch to the proper size, the input shaft is bigger on the zf so the clutch is a must. Install the trans in place of the t19, and call it good. The zf is a better option then the t19 and gearvendor IMO anyway, less to go wrong if "other people" drive your truck. Most don't know how to use a gearvendor properly if they are not accustomed to them. I like the shifter better on the zf also, the t19 seems to old truckish to me.

 

[The Warden]

I've done the swap also and consider it the best modification I've done to my truck to date. It sounds like you have a complete donor truck, which is always good...you'll want the tranny itself, the crossmember, and the floor pan insert from the donor truck, and as DragRag said, you'll want a clutch also. I'm running a LuK single-mass flywheel conversion and am quite happy with it; others have complained about too much rollover noise. Everything else from your truck should be good to go...the clutch hydraulics are the same, and the 4x4 ZF and the 4x4 T-19 are the same length, so you don't need to worry about resizing driveshafts. The 1345 transfer case that's on your '86 will bolt right in place.

Hope that helps some...good luck and post pics!!

 

[Silver Burner]

I did this swap on my old 86 and reused the original SM flywheel and just had it resurfaced. Best thing I ever did to my 2WD. Added the shifter for the 1356 and had this great low range. The gear rollover scared the new owner enough that he took it to a mechanic who told him that he shouldn't drive it at all because it wasn't "compatible"... idiot...but I convinced him that truly that trans was much better than the old T19 that used to be in there and the T-case was priceless on a 2WD. They work great!

 

[Ncgomez65]

Dont have a donor truck. But with income tax coming I'm hoping to to be able to do this. Just wanted to know all the parts I'm going to need. I'm going to need to replace the clutch in the tranny I have now. So I thought If I have the extra money I should just do the swap. For those who have done it. What did it do for your mileage?

 

[War Wagon]

Someday I would like to find a nice reg cab with a 6.9, and I have to say that the #1 upgrade I would do is the ZF 5 swap.

 

[The Warden]

For those who have done it. What did it do for your mileage?

I keep pretty detailed records of my fuel economy. I probably spend 75% of my time on the freeway. I have 4 base fuel economy numbers:

2001-'04 (bone-stock n/a 6.9l, T-19, 4.10 gears, full-size lumber rack in place), I averaged 14 mpg and sometimes got 15 mpg on a good day.

2004-'05 (added non-gated ATS turbo, turned up the fuel, still had the T-19), I averaged 12 mpg and would sometimes get 13.5 to 14 mpg on a good day.

2005-2011 (swapped to ZF5), I averaged 16.5 to 17 mpg, and if I could keep the speed to 55 on the freeway, I could just barely break 20 mpg.

2011-present (removed lumber rack and replaced tires near the end of October 2011), I've averaged 18 mpg, but that's over the course of only filling up 3 times.

In short, the final dependency is on your right foot, but IMHO a ZF swap will almost definitely raise your fuel economy...by how much is up to how you drive. I can give you more detailed records if you want...

 

[IDIDieselJohn]

Since your truck is 4x4, you will also need a 4x4 ZF5....