Topjimmyk

Okay so i need to flush my tranny, and i went to auto zone to see how many quats i needed. well on the computer there was two different transmissions and one took two quats and the other 4. so how to i tell what one is mine on a 98 cherokee sport automatic trans, 6cly 4x4

trans_am7935

i dont know any transmission in the world that takes only 2 quarts, just fill it with 4 quarts or till it spills out the fill hole.

JeepingDan

well....... I think 6 - 8 quarts should do it. Somebody correct me cause I'm not positive. But over filling it can cause damage.

JeepingDan

are you talking about a auto or stick?

5-90

You have the AW4, which has a four-quart "service fill" (eight quarts for a "dry fill.")

This means that pulling the plug and removing the sump for cleaning should only require four quarts to fill back up. This seems to have some variation - so I'll usually say to buy five, dump in three. Warm it up and check the level - you'll probably need one-half to one additional quart. (The fifth usually ends up as a spare - you only need it if you leave the sump off and let the case dribble for a couple of days or so.)

For a flush, replace one pint (one-half quart) of fluid with one pint of Berryman's B-12 "Chemtool," run for about a 5,000 miles, and change while hot.

If you're thinking about a shop "powerflush," know that reports from the field on that process for the AW4 are mixed (but tend toward the negative.) I therefore don't recommend it. With only twelve years behind it, you shouldn't have accumulated too much crud, and the chemical flush should serve.

After the 5,000-mile B-12 flush, you can consider swapping to a synthetic fluid - which should last rather longer. 98K on the engine is a little late for an easy engine oil swap (there may be crud backing up a seal somewhere that will be flushed away by the synthetic,) so I'd do a flush on that as well - change, but replace one quart of engine oil with one quart of Marvel Mystery Oil. Run 3,000 miles. Change to synthetic, using a good brand. I prefer Valvoline or Castrol.) Unless you're silly about towing or hauling, you should then be able to swap to a 15,000-mile change interval - which will justify the cost of the synthetic (conventional service costs twice as much, but lasts five times as long.)

Usual change interval for "general service" on the AW4 is 20Kmiles or so, you can pull that out to 50K by switching to synthetic. You can push it out to 75K if you add an external cooler with a thermal bypass valve and eliminate the in-radiator OEM cooler. Then, you'll be doing about the same thing - pay twice as much for the fluid, but it will last 2.5-3.75 times as long. So, you're still coming out ahead.

Similar changes can be made in your axles - and most synthetics are rated NLGI GL-5 anyhow. Unless you do a lot of towing or hauling, 100K change intervals on synthetic gear oil in axles aren't that uncommon.

Sometimes, you come out ahead in the long run if you spend some more up front (stick to Wix or Baldwin for filters, by the by.)

As far as the transmission "filter" goes, it's really just a sump strainer. So, you won't really need to replace it - just clean it and put it back. If you want a good filter, tap into a coolant line and install a remote spin-on element. Be sure to mount the filter open end up (so it won't spill when you take it out,) and pour the new filter full before you spin it on.

trans_am7935

when you fill it to the top of the fill hole then it is at perfect level, hence why the fill whole is there...someone has never read the service manual before what do you think the term "top it off" means?

5-90

Emphasis mine

Speaking of reading, the original post gives useful information as well. That's how I know that he has the AW4, and that's how I know that the "bottom of the fill hole" idea is invalid in this case. The AW4 is filled through the dipstick tube - if you fill it up to the bottom of that fill hole, you're going to leave your transmission hideously overfilled, and you'll probably be replacing it in a month or so (if you're lucky, it's just going to belch out all of the excess fluid and you'll leave a trail for the EPA to follow around. But, paying an EPA ticket is going to cost more than replacing your transmission...)

Topjimmyk

So basically just drop the pan, clean the filter and im going to buy 4 quarts of lucas atf. what bout the tcase should i replace the fluid in that too?

98 JeepJeep

i would...T-Case only holds about 1 Quart...

IMO i wouldnt mess with the "screen" inside the pan the best thing you could do is drop the pan and clean the 2 magnets in the bottom.

Than Refill with 4 quarts of fluid I use Valvoline High mileage. With my External cooler and 35's and stock gears i rarely see temp higher than 150 (so far)