C4 Transmission won't shift

[hvanorden]

So I picked up my bronco from a guy that left it sitting in a field for two years untouched. I got it running good, but the transmission won't shift out of 1st gear. Do you guys know of any tricks to try to fix this? I have drained the fluid and put new fluid in it along with some of that Sea Foam tranny conditioner. But it still won't shift out of first when I drive it.
Thanks.

 

[rdanford]

Try a vac modulator first, its a cheap try.

After that...its a rebuild...I just had mine rebuilt and couldn't be happier.

 

[Crimson66]

Trans.

I would reach out to Viperwolf.

 

[Viperwolf1]

See if there's vacuum to the modulator first. Hose is probably rotten.

 

[rustbucket]

I have had the same exact problem. Vacuum hose disconnected, and it wouldn't shift.

 

[Rox Crusher]

I would reach out to Viperwolf.

Here in Colorado we have a special C4 search light specifically for reaching out to Viperwolf at night

 

[hvanorden]

Here in Colorado we have a special C4 search light specifically for reaching out to Viperwolf at night

Ok so I'm new to this forum so excuse my ignorance. But what is Viperwolf? And where is the switch to this colorado search light?;D

On a serious note, I will check to Vac mod and see what I find. Thanks for the advice!

 

[Rustytruck]

If you pull out the vacuum modulator you will wear alot of tranny fluid so be prepaired. There is also a small rod behind the modulator so make sure its there and it gets put back in. If you have to replace it you will want a green stripe unit. If there is tranny fluid in the vacuum line to the modulator then you will definitely need to replace it.

 

[Viperwolf1]

Here in Colorado we have a special C4 search light specifically for reaching out to Viperwolf at night

I really dig the special infrared goggles I need to use in order to see the light too.

 

[rustbucket]

Check the hoses that go to the vacuum modulator first. Not as messy, and usually the culprit. Just trace it from the modulator to the carb. If they look old and dry, which, if they are original, they probably are, just replace them.

 

[hvanorden]

If you pull out the vacuum modulator you will wear alot of tranny fluid so be prepaired. There is also a small rod behind the modulator so make sure its there and it gets put back in. If you have to replace it you will want a green stripe unit. If there is tranny fluid in the vacuum line to the modulator then you will definitely need to replace it.

OK I should have read this post prior to working on this. I was so excited to see if this was the issue that as soon as I got home from work I got under my bronco and sure enough there isn't even a tube between the tranny and Carb. Its totally missing. So I thought I would pull out the modulator and inspect it. So I unscrewed the bracket holding it in and reached up and pulled it out and next thing I know there is a stream of fluid pelting me square in the chest! It made quite the mess. I only wish I had it on video so that j could watch it and laugh at myself! Then I cleaned up and came in to look at this forum and read this comment. I laughed again.

OK so one more question. What type of line should it be? Is rubber OK or should it be steel tubing? Also should I replace the modulator since it has been sitting for so long? Are they expensive?

PS. Please free to laugh at my expense. I did, and so did my wife. when I walked in the house with a pink tinted jacket.

 

[rustbucket]

I can't imagine them being that expensive, but I haven't priced them. Rubber lines are okay. There should be steel lines attached to the transmission, though. I'm not sure where to get them if they are missing. Rubber should function fine, though.

 

[YNOTBOB2007]

Just replaced mine...about $10 at your local auto parts store. There is also an adjustment inside the modulator if your shifting is too hard...should be instructions with it.

 

[Viperwolf1]

A rubber line is ok if you can keep it away from the exhaust heat. Steel tubing with short sections of rubber at the ends is better. It needs to go to full manifold vacuum, not the carb. Test the modulator to see if it holds vacuum. New ones are about $15.

 

[Rustytruck]

You're not the only one thats pulled the plug and got the red flood. Throw the jacket away it doesn't wash out. At least 20 years ago when I did it my sweatshirt didn't come clean. One good thing, you will only make this mistake once. It gets embedded in your brain.

 

[Louie76]

anyone ever disconnect the vac hose for off road only? i only ask cuz when i was dickin around under the hood i forgot to put the vac line back on and went for a rip in the feild and the thing shifted....well almost better for off road. it would down shift way earlier and hold the gear longer on accel. a lil annoying when your just idling around but thought it would be nice for peddaling it in the mud without the trans shifting constantly. just a thought

 

[hvanorden]

Does anyone have a picture of where the line should hook into the manifold?

 

[deltarat]

Here in Colorado we have a special C4 search light specifically for reaching out to Viperwolf at night

I hope he and Batman don't get their lights confused, but I think Viperwolf could handle the Joker if he had to.

 

[Louie76]

can hook it to any port on your intake manifold (thats not for coolant obviously) usually the one behind the carb is easiest

 

[hvanorden]

can hook it to any port on your intake manifold (thats not for coolant obviously) usually the one behind the carb is easiest

How big of a line should it be?