Hard shifting 1st -> 2nd gear with ZF-5

[eldonderino]

Hey all.

I recently bought a 1994 F250 it's got 4.10 and a ZF-5 transmission. Clutch was replaced a couple years before I purchased it.

It's been rough shifting to and from 1st and 2nd gear, no grinding, just hard to move the shifter into gear. 3rd, 4th, 5th all pretty easy. It's not too bad, but a pain in the ass when i'm in the city.

If I shift 1st -> 2nd around 1500 rpm being very delicate it's OK, but it's takes me so long the rpm drops and if I give it too much throttle it belches out a cloud of smoke. But at the moment I've figured out if I take it real easy on the throttle I can get by. It seems to shift better while going up a hill maybe around 1800 rpms.

• I shifted it through all the gears while not moving 1st and 2nd still slightly awkward but not too bad, definitely easier than while driving.

• The Clutch pedal begins to actuate a bit below halfway down (not sure if that's normal or not)

• It's usually goes into reverse easy, sometimes I need to roll forward a bit and try again when it won't go in.

Anyone have any advice on where to look. it sounds like the clutch is often an issue considering trying to re-bleed the clutch, what about gear shifter linkages?

 

[franklin2]

Why are you using 1st gear so much? While it's not as slow as some of the granny gears in some of the other trannies Ford used, it is still somewhat in that category. The gear ratio spread is what is causing your problems, there is a lot of difference between 1st and 2nd.

I have to use 1st gear to get going in my truck, it has 4.10's with 35 inch tires. But when I use it, As soon as the truck is moving I shift to 2nd gear. If I rev it way up, I do struggle to get it in 2nd. If you need 1st to get a load going and then want to shift it on the fly later, you will have to hold a little pressure on the shifter and wait for it.


ZF 5 Speed Ratios & ID
Type 1st 2nd
S5-42 Close Ratio 4.14 : 1 2.37 : 1
S5-47 Close Ratio 5.08 : 1 2.60 : 1
S5-42/S5-47 Wide Ratio 5.72 : 1 2.94 : 1

 

[eldonderino]

Hey thanks for the reply.

Well that clears that up. I've only driven modern diesel, and nothing with a gear ratio like this. I was worried about lugging the engine out cause I often see a cloud of smoke if I'm in second gear at a slower speed, but I think I'm just a bit heavy footed.

I haven't had much time behind the wheel yet so I'll have to mess around a bit, and I think ease onto the accelerator in second a little more.

 

[ifrythings]

I would be checking you clutch rod bushing and pedal box bushings for slop, your clutch pedal should be doing something before half way down.

 

[eldonderino]

I would be checking you clutch rod bushing and pedal box bushings for slop, your clutch pedal should be doing something before half way down.

Ok thanks. I will look those over. I forgot to mention the clutch pedal fell almost to the floor one day when I was driving, and then went back to normal after about 5 minutes. I'm assuming there was a bubble in there that worked its way out. So I'm planning on re-bleeding the system if everyone looks alright with the slave/master cylinder/ and pedal.

 

[The_Josh_Bear]

+1 to the above info! All good stuff.

Another consideration is to check the transmission fluid. Some people put standard gear oil into these ZF5's and that's no good. Synthetic ATF or a synthetic MTL will do you well. For that matter if the PO was towing a lot or just never changed it even the best lube could use a change out. I recently did this on mine-- already had Redline MTL for about 60k and changed it out for the same thing, it's much smoother under the same conditions. My synchros are pretty bad in 2nd and 3rd but the MTL has nearly stopped all wear.
ZF says 40K service intervals if towing a lot, which I do.