C4 input shaft question

tonytheplumber · Aug 15, 2018

So I got my trans back from the rebuilder today and realized that the hole in the end of the stator is supposed to house an input shaft. I don't know if the trans from this project truck ever even had an input shaft, but I know it doesn't have one at the current time. I don't think I would have misplaced it, but if it was in the old torque converter when I trashed it and somehow didn't catch that, it's long gone. So, due to past experiences with ordering the wrong parts I'd like to know if one of you gentlemen would happen to know what input shaft I need? As in, what application is the correct one. Do I need to just do a spline count?? Are they all the same?? Are there different lengths? I learned my lesson on the flex plate and starter debacle I just went through. I don't want to be ordering the wrong part. AGAIN

Thanks in advance!

Viperwolf1 · Aug 15, 2018

The 64-69 input shaft is 24x24 spline and smaller in diameter than later shafts. The 70 shaft is 26x26 spline. The 71 and later shaft is 26x24 spline. All Bronco C4s had the last one, when they left the factory.

FordBronc · Aug 16, 2018

https://www.wildhorses4x4.com/category/Bronco_Automatic_Transmission

https://www.wildhorses4x4.com/product/C4_to_Bronco_dana20_Adapter/Bronco_Automatic_Transmission

http://www.advanceadapters.com/prod...-77-bronco-dana-20-transfer-case-adapter-kit/

https://www.dufftuff.com/Adapters_E....htm?searching=Y&sort=1&cat=57&show=40&page=1

Good info: http://www.earlybronco.com/technical-articles/3-speed-to-a-c4-transmission-swap/

Someone should have and sale just the shaft you need. I believe there is a difference in a auto or manual "spud" shaft.

See. https://www.tomsbroncoparts.com/product/output-shaft-c4-automatic-new

bax · Aug 16, 2018

FordBronc, The OP was asking about input shafts. You are posting up tail shaft adapters. All good info but lets understand were looking for an input shaft. Viper had some good information. I have had the input shaft problem before. You don't always get a "Bronco" transmission in a bronco. The OP needs to figure out what year c4 he has so he can get the correct part.

Broncobowsher · Aug 16, 2018

And possibly what year parts were used in the rebuild.

I would ask the rebuilder if they have an input shaft for the transmission. Good chance they have one just laying around. They are a loose part. No retaining clip or anything. Just slip it in.

Rustytruck · Aug 16, 2018

I ran into this problem swapping out a wrecking yard C4 when I was a young one in my 67 Mercury Caliente. All the shafts look the same to the casual eye. Converters look the same but swapping parts gets goofy. Ford does this on purpose to mess up your day on a simple project.

FordBronc · Aug 16, 2018

Yes oops it was early and my coffee was not done...in fact I think I was still asleep even though I was already at work. lol

tonytheplumber · Aug 16, 2018

Viperwolf1 said:
The 64-69 input shaft is 24x24 spline and smaller in diameter than later shafts. The 70 shaft is 26x26 spline. The 71 and later shaft is 26x24 spline. All Bronco C4s had the last one, when they left the factory.

I did a spline count on each seeing as how I don't know the cobbled together history of this truck. The trans is indeed 24 spline (technically 22 since there are 2 blanks

) and the converter is 26. I ordered a new TCI piece from Summit.

bax said:
FordBronc, The OP was asking about input shafts. You are posting up tail shaft adapters. All good info but lets understand were looking for an input shaft. Viper had some good information. I have had the input shaft problem before. You don't always get a "Bronco" transmission in a bronco. The OP needs to figure out what year c4 he has so he can get the correct part.

True story on not knowing whether of not this is a Bronco trans. Lord only knows.

Broncobowsher said:
And possibly what year parts were used in the rebuild.

I would ask the rebuilder if they have an input shaft for the transmission. Good chance they have one just laying around. They are a loose part. No retaining clip or anything. Just slip it in.

He didn't have any laying around. He builds a lot of high performance torque flights so he likely has scads of old mopar parts laying around.

Rustytruck said:
I ran into this problem swapping out a wrecking yard C4 when I was a young one in my 67 Mercury Caliente. All the shafts look the same to the casual eye. Converters look the same but swapping parts gets goofy. Ford does this on purpose to mess up your day on a simple project.

They have ruined my day on many occasions lately

FordBronc said:
Yes oops it was early and my coffee was not done...in fact I think I was still asleep even though I was already at work. lol

All good. I greatly appreciate that you were willing to post those links in an effort to help out.

Viperwolf1 · Aug 16, 2018

Post some pics of the trans. The shift lever is unique to Broncos. There is a date code cast into the case above the shift lever. All Bronco C4s also had an H cast into the servo on the right side. It should also be a pan fill case. Bellhousing attaches with 5 bolts separate from the pump bolts.

71sport408 · Aug 16, 2018

These fellows are much more knowledgeable than myself but I have purchased and used C4 input shafts from Performance Automatic. Not sure what amount of horsepower you are putting it behind but I ended up going with a hardened input shaft. This was a while ago however so I can’t attest to their current offerings. Just thought I would throw it out there.

tonytheplumber · Aug 17, 2018

Viperwolf1 said:
Post some pics of the trans. The shift lever is unique to Broncos. There is a date code cast into the case above the shift lever. All Bronco C4s also had an H cast into the servo on the right side. It should also be a pan fill case. Bellhousing attaches with 5 bolts separate from the pump bolts.

Look like a Bronco trans?? I currently have the bell removed while I sorted out my starter and flex plate issues. It does NOT share fasteners with the pump. And this is a pan fill model.

Sorry the pics came out sideways

tonytheplumber · Aug 17, 2018

71sport408 said:
These fellows are much more knowledgeable than myself but I have purchased and used C4 input shafts from Performance Automatic. Not sure what amount of horsepower you are putting it behind but I ended up going with a hardened input shaft. This was a while ago however so I can’t attest to their current offerings. Just thought I would throw it out there.

I ended up ordering a hardened shaft by TCI from Summit. I doubt I will be making enough power to hurt a stock shaft, but I would hope the hardened shaft would be as strong if not more so than stock. I definitely did not want the cheapest one I could find.

Rustytruck · Aug 17, 2018

Looks like a Bronco case from 1975.

Viperwolf1 · Aug 17, 2018

Rustytruck said:
Looks like a Bronco case from 1975.

Yes. Early 75 Bronco. Correct style case, levers and year range.

tonytheplumber · Aug 17, 2018

Rustytruck said:
Looks like a Bronco case from 1975.

Viperwolf1 said:
Yes. Early 75 Bronco. Correct style case, levers and year range.

Thank you gentlemen for delivering some good news to me! Considering I've already had it rebuilt ;D
Thank you guys again for your wealth of knowledge!

C4 input shaft question

tonytheplumber

Jr. Member

Viperwolf1

electron whisperer

FordBronc

Bronco's, yea I have a couple.

bax

Old Member

Broncobowsher

Total hack

Rustytruck

Bronco Guru

FordBronc

Bronco's, yea I have a couple.

tonytheplumber

Jr. Member

Viperwolf1

electron whisperer

71sport408

Sr. Member

tonytheplumber

Jr. Member

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tonytheplumber

Jr. Member

Rustytruck

Bronco Guru

Viperwolf1

electron whisperer

tonytheplumber

Jr. Member

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