Good afternoon, I am new to the bronco world so forgive me. I was told I was buying a C4 and Dana 20, but I believe I ended up with a C5 and Dana 20. I am unable to decode the transmission tag, and the bell housing has two sets of bolts inside. From what I understand that means C5. Any help would be appreciated if I ended up with the wrong transmission I'm still on the hunt then for a C4.

 

So I did not know about a "C5 transmission) until you said that is what you had. Then I Googled it....and found lots of talk about it in a early Mustang forum. These are statements from it. So if it is a real C5 looks like it was a swap in for some off reason. I am trying to decode the tag....

-I thought those were Ford's first Overdrive trans. Those were only around for a few years 1982-1986. I think the only difference in a c5 to a c4 is the torque converter has a clutch for cruising, and maybe some slight changes in the valve body.

C5 Built from 1982 - 1986 Case length same as C4 but pan has a hump in it whereas the C4 has a flat pan. Not an overdrive tranny. Not even that widely used. Avoid.

The added clutch is in the torque converter. It simply locks the input shaft of the trans to the housing of the torque converter. Thereby giving you a 1:1 connection between the crankshaft and the trans.

It has no real performance value. It was designed as a fuel\ saving measure. Most lock-up converters lower engine rpms 100-200 rpms at cruise.

Actually, the C-5 is a decent transmission if you are going to use it to just cruise around. When I worked as a parts back counterman at a friendly Ford dealer, I rarely saw a C-5 overhaul. Lots of AOD, E4OD, AXOD's, etc...

It's basically a C4 with the ability to "lock" in high gear cruising. Thus a car with a C5 will achieve a bit better highway mpg than it would with an equivalent C4. No big difference, but measurable. This added ability to lock in makes a C4 the better choice for high performance use (drag racing in particular). The locking ability means shock loads are more likely to cause internal damage versus the C4 which can slip a bit more and better absorb hard shocks (IE losing then regaining traction while accelerating). At least that was what people figured what happened when we were breaking them back in the 80's. Although C5's share most internals with C4's, the entire valve body is completely different. Thus the widely available C4 shift kits can't be used. I don't believe anyone ever bothered producing a C5 shift kit. Years ago, folks would swap valve bodies so they could use a shift kit. Surely somebody still remembers how this was accomplished. I can't remember if it was a straight bolt-in or not. If your C5 does what you expect of an automatic, enjoy and don't worry about it. I consider the C4 the be the very best all around Ford transmission ever made. A C5 is a C4's half-brother, so it's pretty darn good.

The C4 and C5 are pretty closely related. The lockup TC is pretty garbage, as it's a very heavy unit and hurts performance. The valve body being a different design also hurts simple performance potential with a cheap shift kit. But there are a few features that do make it even stronger than a C4, and they're actually sought after by knowledgeable transmission builders, and they can handle a lot of power!

Also is the Dana 20 transfer case a T or J shift pattern? Looks like a T shift with the 2 tabs (one per shift rod). So that equals easy to twin stick, just so you know.