2nd to 3rd shift problem

[mechanics kid]

I have a 1999 Jeep Grand Cherokee with 88,000 miles that for the past 6 months has had a delay in shifting from 2nd to 3rd, it is getting progressively worse. When I let off the gas, it shifts on it's own, if I push it, it jerks hard into gear. Other than the rotors I haven't had any problems with it other than normal wear and tear. My dad fears new trans is needed, without him getting to look at it. The trans shop agrees and I'm looking at $1500. Anyone have any other ideas as to what could be wrong.

Thanks!

[dksob81]

I have no clue, but I have a similar problem with my 94 ZJ, mine shifts ok when I lay on the gas, but normal driving (slow), it acts funny, it shifts into 2nd good but then about 3mph later it shifts again, like it is shifting from 2nd-3rd, which at about 16mph seems a lil early. and it is a slow shift also (like it's slipping). I don't have'nt had the money to get it looked at lately or I would have. but now it's gonna have to wait till after the new year.

[fredjacksonsan]

Some people say never change the fluid, but my brothers and I are fans of clean fluid. In your situation I'd consider dropping the pan, replacing the filter and refilling the fluid. If you're mechanically minded, you may want to consider putting a shift kit in the trans, which will likely help out with the shifting. In either case, clean out what gunk you can find.

[fredjacksonsan]

Since an auto trans is operated by pressure, that's why the beast behaves differently at different throttle pressures. Worth it to try the new fluid rather than pay the $1500 up front.

[dksob81]

yea, Fred I know what u mean, i changed my fluid and filter maybe 3000 miles ago, b/c of this and it didn't help at all. I can't remember when this started, I think it started after I got the jeeper stuck.

[fredjacksonsan]

AHA....stuck and spinning I take it? You may have a problem, but I'd still want to try the $90 shift kit and a long afternoon to install it before paying $1500 for a trans rebuild.

[dksob81]

yup thats it i had it burried over the bumpers, I would have made it thru but I hit it going a lil to fast and it was like hitting a brick wall, and too all my momentum away.

[fredjacksonsan]

Ouch - brick wall. So no problem before the mudhole, prob started right after....did you get water in the trans do you think?

I like to tell the (true) story of a friend that had an old car with an auto trans. It was acting funny, he changed the fluid, no change but the fluid was an odd color. Three weeks later, he changed it again and again it was an odd color. He changed it twice more in the next couple months, until it was the right color when he changed it. Then he was sure that the new fluid had been circulated throughout all the channels and the torque converter. After that, he then drove the car for several years without trans problems.......so that's why I believe in fresh fluid.

[dksob81]

yea, I am thinking of having the tranny flushed, the dealer wants $130 to do it. but on the other hand there are many horror stories about flushing the tranny when a problem is visible it just causes mor eproblems. but I have another tranny for it, so I thik I will have it flushed and if that don't help then I will let it go till I can afford (after the new years) to have it looked at, but if it makes it worse I will just change the tranny.

[Cam7]

One of the first things of delayed shift is burt fluid. Another possibilty is the governor valve sticking and front band needs addjustment. I agree with Fred try a shift kit and fluid, filter change.
I got my chevy truck stuck in the snow 2WD and had same problems. Changed filter, fluid, shift kit and a booster valve I got of E- Bay = Fixed problem solved. Havent seen the booster valve for JGC Trans it worked on mine. Ive heard of mechs taking off the trans lines off the rad and starting the vechile and letting it run for a few seconds after the pan and filter is off! Never tried it supposed to work. Cheaper than 130 or 1500.

[dksob81]

I tried to adjust the band (adjustment inside the tranny) but the adjustment screw is square not hex, so I think I am gonna have to get a crowsfoot wrech to adjust it with the torque, etc...

[mootjr]

I have the exact same problem with shifting on my 99 GC, 4.0L I6, 2x4 with only 51K miles. Dealership diagnosed problem as internal seal failure in transmission and quoted soft rebuild price of $1500. Transmission shop will do a complete rebuild for $1300, gotta love my dealership. My local mechanic recommends replacing transmission instead of rebuild for the sake of cost. Does anyone know if 2000-2003 42RE transmission will work in 1999 model. Are there additional modules or sensors that have been added in recent years?

[Myrtle Beach]

mechanics kid- What kind of tranny do you have?- Do you have a 6 or a V8?

[mootjr]

I have a 6 cylinder.

[Off_Road]

Fred does have the right idea. Throttle preasure effects shift timing and shift quality. Under normal acceleration, medium throttle preasure the 1-2 shift should be between 18-20 mph. The 2-3 shift somewhere between 28-30 mph. Then the clutch inside the locking torque converter should kick in, and finally your 3-4 overdrive shift. Under those conditions the shift should be firm, but not hard. Faster acceleration increased throttle preasure would equal more of a firm shift. It's best to have a transmission shift firm and solid rather than soft and mushy not even feeling the shift as some luxury car owners prefer.

Of course the obvious very first thing to do is to check the fluid level and quality. Is the fluid normal in color? Or is it slightly brownish at all or burnt? What does it smell like? Does it smell burnt? If there are any signs the fluid is burnt then most likely your problem is internal and would be associated with the direct clutch pack. The direct clutches are applied in both third gear and also when putting the transmission in the reverse detent.

Have you noticed any changes when engaging the transmission into reverse? You might not notice a problem in reverse yet, because there also is what is called a low-reverse band that also is applied in reverse. This band is applied in manual low and reverse only. The other band in the trans is called the intermediate band and applied in second gear only. On some transmission also known as the 2-4 band. Applied in second and forth only.

If you are having internal clutch failure within the direct clutch pack you don't want to install a shift kit. When experiencing any internal clutch faliure the installation of a shift kit will only advance your problem. It will not prolong or delay any further internal damage.

Usually the fluid is your best indicator, depending on it's condition. Hopefully your fluid is in good condition. Then as Fred had mentioned a throttle preasure adjustment might very well take care of your problem.

Best of luck to you.