Allright people, first off, I am new to posting on the jeepforum, although I have always stopped by for quick answers. I recently got me another jeep that I'm eventually gonna start building, so I figured I would join and learn as much as possible along the way. So here is some history on me real quick... got into jeeps in 2003 with a 97 TJ 4.0, 4" suspension lift, 33x12.50, blah blah blah. Gas got pricey, sold it (regrettably).
Now I got me a 93' yj. Love it, except for the 4 banger (we will get into this later) I do not know a lot about rebuilds on my own, always had friends to help me. At any rate, here is my question to start off....
I bought the jeep knowing she had syncronizers going bad. Gotta let the rpm go down before I shift from 1st to 2nd and so forth. So my question is should I just run them as long as possible and then rebuild the tranny or replace the syncros? Also, I plan on running 33 or 35's eventually so should I regear at this time as well??? When i re-gear, i'll probably go to 4.88's.
Thanks for any help and please remember, I am not incredibly knowledgable YET about tech stuff, so go light on me at first. I'll add some pics soon so you know what I'm starting with.
Welcome to the forum and congrats on getting another Jeep. I would go ahead and get your tranny fixed unless you are swapping engine/trans soon. As for gearing, I would wait until you get your new tires.
I've always been taught to make it right before I go and try to make it better, unless you can make it better while making it right.
I'll answer the easier question first. You may not like the results if you re-gear for 33's or 35's and keep running a smaller tire. You'll end up having much higher RPM's at highway cruising speed. (ie 30" tires and 4.88 gearing @ 70 mph will result in an engine rpm of about 3k)
You can play around with the numbers here to see what it would actually be for your current tires. I would suggest collecting the gears and master rebuild kits, and waiting on the install until after you have the tires. Then, take a weekend and install the gears. Remember that you have to re-gear both the front and the back to the same ratio or you will have some issues with 4x4, and maybe even cause some issues (ie breakage).
TBH, rebuilding a transmission or re-gearing an axle are probably a bit above and beyond for a relative beginner. Though you can find at least one solid walk-through for re-gearing and probably a couple for rebuilding an ax-5 here on the forum.
Have you tried Synchromesh from Penzoil in your transmission? I had the same grind when I shifted into 2nd, and it instantly went away after I changed the fluid and filled the tranny up with Penzoil.
At first, I didn't like my four squirrels. Then I noticed a fuel, dare I say, economy of 10 MPG, and realized that I needed to address some things with the engine. Long story short, If given the engine some maintenance type attention, and its running much better now. I have a couple things left to do to it, which I hope will make a bigger difference, but even at this point, I am not sure I would notice a real lack of power on a closer to stock driveline.
With the 4cyl, you will want to gear it as deep as possible if your planning on running 33's or 35's. This will keep it driveable. With a 6cyl on 35's its a good match. The caveat to this is do not waste the time or money regearing the D35 rear axle or "upgrading" to a Super 35 kit. If you want to go to 33's or bigger go straight to the ford 8.8 from an Explorer.
As for the tranny, I would run it. The benefit to driving with bad synchros is that you will invariably learn how to drive without a clutch. When you match road speed to engine speed for the gear you are trying to get into it will slide in. This is how big trucks get a few hundred thousand miles on one clutch. I did it every day with the old jeep and never had a problem. I would run it unless its really bothering you. If it is then get it rebuilt or get another one to replace it.
I would not put 35's on a 4 banger. Regear yes .Rebuild now.The worst thing to do is wait till it breaks, and then fix it.Things that are not breaking, get broke when waiting,and then it's to late. Seen a connecting rod push through a block because there was only alittle tick in it.Cost is better for prevenative mechanics than repair mechanics,or full on replacement .Cause you never know if that engine or tranny swope is going to last beyond the 30 day warrantee.