C4 Rebuild Time

[pcf_mark]

The seals are all plyable and soft. The pump gears looked beautiful - not a nick or scratch. The non chamfered edge was a sharp corner with no wear. The sealing rings were not broken on the back of the pump. Even the bushing was great. Any way to test the pump?

I just finished disassembling the valve body and I am pretty sure it has some type of shift kit in it. The high speed kick down ball was missing and it has a small white plastic disk that is not mentioned in the manual (but it is mentioned in the parts kit). Also the transtion valve in the manual is solid but the one I have is hollow on top with a spring. I was planning to put the balls back per the manual and the white disk per the kit instructions.

One other thing that may not be important - intermediate servo accumulator valve (clearly I am looking at the manual - thank you again) was tight in the bore and did not move freely so I was going to polish it before re-installing.

 

[Viperwolf1]

You can measure the pump wear with a straight edge and feeler gauges. I think the spec is in the manual.

Other than that check the input shaft splines and where it fits into the forward clutch. The clutch hub can crack and allow the input shaft to spin. Possibly a bad converter also.

Follow BwoncoHowie's tech article on the valvebody.

 

[pcf_mark]

I have read BroncoHowies tech article and I am going to follow that.

The input shell is solid with no cracks or wear. The input shaft looks good with a little rust out at one end. The pump body was also very rusty. If water got inside could that make it slip? It was dry when I opened it up.

I cleaned the TC today with solvent. How can I inspect the TC? It spins with the input shaft by hand in both directions and is not making any mechanical crunchy noises. I hate to throw money at a problem!

I will double check the pump wear with a straight edge and feeler gage.

 

[Viperwolf1]

Only real way to check a converter is to cut it open. You can get a rebuilt stock converter for $50. I recommend it with a fresh transmission because the converter can hold lots of crap in it.

 

[pcf_mark]

$50 sounds great - do you have a source? I have seen them for $175 online. I will try to find one locally this week also because the shipping may be tough.

 

[Viperwolf1]

Transtar

 

[pcf_mark]

I ordered one today $88 shipped to my door. I believe it was bad because I could turn the input shaft both directions.

Explains a few things if it really is broken. Maybe the last guy rebuilt the trans and it did not work so he took it out and sold it. The trans looked really great inside and all the seal are nice and pliable. All new guts now anyway pending the washer kit to get it all back together.

I could not find a spec for inspecting the pump. Simply replace bushing, seal and inspect gears for damage.

 

[73azbronco]

True, make sure you use the gasket on the pump housing to case, sometimes people forget, then it leaks like crazy. Front of pump body is usually rusty, it is exposed to elements in bellhousing.

I missed it, did you rig up or buy a tool to compress the clutch packs? Replace the clutch piston seals?

 

[pcf_mark]

I rigged up a 3" piece of 1" angle iron and drilled two holes in it. Then I put two 3" screws in the holes with a nut on both sides to basically make a U looking fixture. Then I put this and the drum into my el-cheapo Harbor Freight press and compressed the piston. Work great!

Because I did not know what was wrong I am replacing all gaskets, seals, frictions, steels and thrust washers. Several bushings also. I am waiting on the thrust washer kit and I can re-assemble.

When I talked to converter people they said it may or may not turn both directions sitting horizontal but if it is vertical (in the car position) it should only turn one way. Mine turns both ways all the time and in the vertical position it clicks in one direction. Hopefully I can get all the bits together this week.

 

[fungus]

Nice job pfc. I'm investigating a C-4 build for my family crawler and I've got a buddy willing to hook me up w/ one from a '77 that he's (his wife) is anxious to get outta his yard. Does anyone have a soft copy of the C-4 manual they could post up or PM me? Trying to get my brain wrapped around what I'm about to get into.

Thanks,
Fungus

 

[pcf_mark]

The super good news - my is rebuit and ready to go back in the Bronco! Passed all the air checks and I am getting ready to put it in tomorrow. Additional good news is my rebuilt converter was only $78 and my old one was toast.

On the advice of this board I also bought a transfer case to C4 seal. I did not know where it was exactly or if it was bad but now seamed like the time to put a new one in.

Now that I have separated the t-case to t-case adaptor I do not know how to get at the seal. It looks like you need to open up the transfer case and install it from the inside. Looking at the t-case there is a male flange that locates the transmission that sticks off the t-case about 3". In the center is the splined part that mates to the output shaft. Looking down into this the seal is down there a ways! Any advice?

 

[Viperwolf1]

Now that I have separated the t-case to t-case adaptor I do not know how to get at the seal. It looks like you need to open up the transfer case and install it from the inside. Looking at the t-case there is a male flange that locates the transmission that sticks off the t-case about 3". In the center is the splined part that mates to the output shaft. Looking down into this the seal is down there a ways! Any advice?

You need to remove the male flange (bearing/seal retainer) but you don't want to drop the 13 roller bearings into the tcase. Lay the tcase down so the input is pointed up. That way you can pull the retainer out and the bearing won't have anywhere to go. You're going to have to tap on the retainer while you pull to get it out. Once out, remove the snap ring and input gear. Note which way the gear goes on. You can put it on backwards (lots of people make this mistake) but you'll lose high range if you do. Once thats out you will see a larger snap ring near the outside of the bearing. Take that out. Then you should be able to tap the input shaft and bearing out of the retainer. All thats left now is the seal.

 

[pcf_mark]

Thanks everybody - I was able to test this today and I have drive and reverse which I did not have before! It was a short test of about 10 feet because the front brake hose pooped out and I almost went through the real wall of the garage! I am going to get that fixed and tidy up some loose ends on my conversion. Then I can take a longer test drive and see if it changes gears etc.

Thanks again
Mark