Tranny on its way out?

[Vanquish]

I have a 92 XJ with the 5 speed tranny.

Now, first off it makes a lot of funny noises and does some weirds things. To me it just sounds like the sycros are shot, but other have said it needs a general rebuild...

From a stop, its definitely not easy to put it into 1st or 2nd, you pretty much have to force it. 3rd and up, it just slips right into. However, if the truck is rolling even the tiniest little bit, 1st and 2nd are just as easy as all the rest...

Also, theres a sound, which sounds like a release bearing, thats comes/goes when i press/depress the clutch pedal. However it's coming from inside the tranny. When I have the shifter out, you can tell it's inside the tranny, and not the release bearing(what is like 3 weeks old), When you press the clutch its gone, when you release the clutch it's noticable.

Also I've read these are fully syncronized transmissions. Sometimes before putting it in reverse I have to put it into first then reverse, otherwise all I get is grinding, which can be stopped by letting it grind for a second.

Also(yes another one), when on the highway, in 4th or 5th, theres an almost rattling noise in the tranny, but only in 4th and 5th, a lot more noticable in 5th, and MUCH more noticable when on the gas.

Sometimes to me it just seems as if the clutch is out of adjustment, for the hard shifting and reverse things, but I don't see a way to adjust it? Am I dumb or is this design? The clutch itself was replaced around 3 weeks ago, everything.

Any and all information appreciated. Thanks in advance.

 

[Vanquish]

Where the hell do I get these 'performance' so to speak, gear oils? Such as Syncromesh? I've read all these fantabulous things about them, but no one sells anything other than regular ol 80W90...

 

[otto]

Same symptoms with my AX-15, but it does go into first gear OK before a complete stop. Drive it till it drops, or you drop it changing the internal slave cylinder/throwout bearing. Redline MT-90 or MTL is available online for about $8/qt. Try here:
http://www.myoilshop.com/AutoPrds.html

 

[MistWolf]

I'd not advise driving it till it drops- I did that with my old BA-10 and when it did implode, it was so bad it could not be rebuilt. Not that I'd recommend rebuilding a BA-10. I was having trouble with shifting on my NV4500. I took it down & had it looked at. They found synchros & bearings were worn and were able to rebuild it with little trouble.

Before yanking it out & rebuilding it, make sure your master cylinder is in good shape. Some MCs will leak internally which will make full clutch disengagement difficult. You could also be having trouble with your internal slave. But by the time you yank the tranny out for that repair, you might as well take the tranny to a shop & have it looked at.

Did these problems start when you replaced the clutch?

 

[87manche]

I think this is simply a matter of availability.
I can get a lower milegage (60-70K) AX-15 for $200. It would cost me just as much to rebuild the one I've got now, and it's got 250K on the gears.
I'll drive it till it drops, then replace it, and have less downtime than if I rebuilt it.

 

[lawsoncl]

x2 on the Redline or other quality, low sulfur synthetic gear oil. The high sulfur content in GL4 and GL5 attacks the brass synchros and shortens their life. Quality oil makes a world of difference in both the AX5 and AX15, especially for cold shifting. I ran a mix of MTL and MTL90 in mine after I rebuilt it. I agree that you should run it until it won't shift anymore. The only thing you'll chew up are the soft brass synchros which get replaced during a rebuild. The rebuild kit with synchros and bearings runs about $180-$200, btw. I did mine without a press, but I highly recommend one.

 

[Vanquish]

I dont know if these problems started since the new clutch...

When I bought it the slave cylinder leaked, and it wouldnt shift at all..

Heres a question, the manual says 75W90...I'm using 80W90 since I can get it for free, is there seriously that big of a difference between the two?

 

[otto]

No, but what's important is to use oil that is NOT rated GL-5. A $30-40 investment in MT-90 or MTL is worth it for easier shifts and longer life.

 

[lawsoncl]

I dont know if these problems started since the new clutch...

When I bought it the slave cylinder leaked, and it wouldnt shift at all..

Heres a question, the manual says 75W90...I'm using 80W90 since I can get it for free, is there seriously that big of a difference between the two?

So is it possible that the previous owner tore up the synchros by ignoring the clutch problem? When I bought my MJ, it had a brand new clutch and a tranny in bad need of new synchros. I believe the previous owner ignored a bad clutch way too long, tore up the synchros, and the dumped it when a new clutch didn't fix grinding going into gear. The synchros were badly worn and the notches where the fingers grab were ripped up. The gear oil glittered with brass shavings.

 

[Vanquish]

The oil I'm using IS rated GL5 I do believe. Thats the problem right there? Or is that a precaution ary measure because over time is causes damage?

Also I replaced the clutch in this, I could watch the salve cylinder leak, it isnt a story from the guy I bought it from.

What are some tell tale signs your syncros are shot, compared the using the wrong fluid? I want to collect as much info as I can before going out and spends $60+ on gear oil.

Also tonight I noticed that the longer you drive it, the harder it gets to put into the first 2 gears. If that helps with the symptoms at all...

Edit: Lets say my synchros are shot, how much would it generally cost for a tranny shop to change them?

 

[87manche]

replacing the syncors is usually part of a master rebuild.
Expect $1k.
find a good low mileage unit in a junkyard.

 

[lawsoncl]

The oil I'm using IS rated GL5 I do believe. Thats the problem right there? Or is that a precaution ary measure because over time is causes damage?

When I rebuilt my AX15, I used cheap GL5 intending to drain and refill after the first week. It shifted so badly, I thought I screwed up the rebuild. After the second day, I drained and refilled with the RedLine and it was a night-day difference. I was quite amazed at the difference in shifting. With the RedLine it shifted great.

 

[Vanquish]

I can't find any of these gear oils...anywhere. The redline website says all Partsources and Canadian Tires within any distance sell MT-90, but I've called and they can't even special order it...

 

[Vanquish]

I bought 4 liters of 75W90 tonight, semi synthetic. The jug says nothing about limited slip additive, but it does say GL-5 and Extreme pressure, since its the only type of oil I can find that isn't 80W90.

I can't really say it's helped out any. I said earlier that the more I drive the truck, the harder it gets to shift. It just gets harder to shift SOONER now...

 

[lawsoncl]

but it does say GL-5 and Extreme pressure

The EP additives are usually sulfur and zinc. You don't really need or want the extreme pressure additives because they reduce the friction at the synchros too much and they can't do their job.

 

[lawsoncl]

Checkout this Redline article, http://www.redlineoil.com/whitePaper/13.pdf. Obviously it's a little biased towards their product, but it does explain some of the issues.