I talked to a friend of mine this weekend and he thinks that the non-engagement problem on my downshifts are an indication that the synchros in the 4 speed gear box are on their last legs. Sound about right? I changed the OD fluid and found about a 1/4 inch of "stuff" on the magnet, although no big chunks...The 4 speed fluid looks clear, although i only dipped my finger in the fill hole.

so is it possible for someone with a factory manual to rebuild the speed? how about the OD unit? Are there any other books that are more helpful? This will be my first time ripping into something like this, but i have pretty good skills, and i can read the service manual.

 

ttt

 

I'm also running the 4+3 (97,000 so far). I'm not sure what your "engagement" problem is. Are you experiencing crunching going from gear to gear? The 4spd side is essentially a BW T-10, they're pretty stout. I would first ensure your clutch is functioning correctly (and the slave/master cylinder). If there's still a problem get a Factory manual first to see what's involved with dissassembling the tranny.

I had to pull my OD apart to exchange the speedo drive gear (gear ratio change). Of course when went to drain the 4spd side, chunks of thrust washer(s) came out too "This is a good thing" I tried to convince myself (good because the tranny was coming out anyway ) Pulling the tranny half-way apart required a complete gear puller set and alot of "trial and error" upon reassembly. The front bearing (iirc) was pressed in, and I about sh*t myself when the counter shaft was bound up TIGHT until the bearing was fully in. I never attempted to remove & replace the synchros......

 

Thanks for the reply!

As far as the non-engagement issue…my problem is that my downshifts don’t “catch” until I hit the throttle. It fully shifts into gear, but there doesn’t seem to be any connection. There’s definitely no “engine braking” going on during downshifts, instead, it feels like the car is coasting in neutral. The other odd related issue is if I am in 3rd for example, and I take my foot off the gas, as I approach the point that I would normally downshift to second, the engine doesn’t start to bog down like it usually does. Instead, the RPMs “blip” as if I was “rev matching” (but I’m not). And finally, when in reverse, after about 4 feet, I get a pretty harsh rubbing/grinding sound accompanied by additional resistance…it almost feels like a tire rubbing a wheel well (but its not). The differential lube looks good and full, and the drift shaft/c-beam aren’t touching.

I’ve slip tested the clutch by putting it in 3rd, running up the RPMs to about 1500 and popping the clutch and the car died instantly, so I feel pretty good about the clutch system being ok. I’ve read and re-read the 4+3 section in the factory service manual and I don’t see my problem described. I’m told that the 4-speed rebuilt isn’t a big deal and I would prefer to do it myself. I also know that people are afraid of the OD unit, but if its more of people being afraid of what they don’t understand and not based in “been there, done that and hated it”, I’d like to try my hand at it and put in the beefier Calloway Twin Turbo parts that were incorporated in the OD unit.

I’d love to hear more from 4+3 owners here…whether they have braved the repair themselves or had it done or anything else that could be shared!

 

I rebuilt mine.You need to get some specialty tools (or make them like I did)There is a real good internet site (i will look for the address or someone else will chime in with it)They dont use as many springs in the rebuild as factory original so it is a good step by step guide(better than the manual)The hardest part for me to find was the gromet for the oil filter!!!Good luck.

 

thanks for the vote of confidence!

and if you order the OD filter kit from Ecklers, it comes with the gromet for the filter/pickup tube....Mid America's filter doesn't

 

Very interesting symptoms I'ld be inclined to think something was going wrong in the OD, too; as I can't see what in the 4spd could cause these problems.

The OD does require some special tools too. I had mine done by some "guru" in upstate NY years ago. It was thoroughly BLOWN when I shipped it off. I have alot more experience now than then, so I would probably try to rebuild it myself if I had to. (Actually I think ZF or a T56 is in my future...

I'll see if I can dig up the sizes of the "special" bolts needed to cage the carrier springs in the OD.

 

If you need any help with the 4-speed, lemme know. Also, the synchros can be checked fairly easily by pulling the side cover off. Shift the car into 2nd gear first so you can remove the 1-2 fork as well. You can use a feeler guage to check the syncrho life. I don't recall what the specs are, somewhere around .050" for a good one.

If it feels disconnected though, it's probably not the 4 speed.

 

You can also get the filter from the local store for about $5-$8. Application, 69 Ford Ranchero with FMX auto trans.

I would not recommend using the Eckler's grommets, they're garbage and will turn to mush and tear easy. I don't know any easy source for the grommet though.

Those reverse issues make it definitely sound like a dying overdrive.

 

Central: Thanks for the additional insight. I remember that you used to have the 4+3 as well. I like knowing what I am in for before someone just starts guessing. I’m going to a vette specialist this week and have them “take a look.” They also said that they are booked 2 months out and I’d have to just “get on a list.” I figure that in 2 months, I can read enough and look enough to figure it out and rebuild it myself. Now, am I right in understanding that the early Calloway Twin Turbo vettes had upgraded OD internals? I figure that anything that was able to handle that kind of HP will do just fine in a stock application of only 230HP. I have been able to find shops online that offer improved OD internals and they really aren’t outrageously expensive, especially when considering the cost of having a shop do it or swapping in a ZF or a Richmond.

Keep checking back here…I’ll post progress and questions as they occur…..