hard shifting when flooring it

You can drive a car easy and have no issues for 300,000 miles with luck, you can put a car on a race track and blow it in 10 minutes. Slamming into gear just doesnt sound righ does it. Try a oil and trans filter change.

Actaully, full throttle upshifts should take place closer to 6,000 rpm. They will be harsher than part throttle upshifts, but it the valve body is operating correcting they should not be particularly jarring. As Mark says, transmission fluid should be clean. Also you could adjust the throttle cable for full open at wide open throttle. When I disassembled and cleaned the throttle body, the manual gave several adjustments. One of these is the throttle position sensor. On my '94 it did require some adjustment.

Yes it is for many higher mileage automatics. Automatic transmissions work by changing gear-ratios using hydraulically operated bands which grab onto drums and clutchs which operate and release. If you an imagine or remember the rear brake on older (as in 40 years ago) kid's scooters where a semicircle of spring steel lined with a friction material is applied around the drum on the rear wheel, hence causing the drum/wheel slow to a stop,..then you have a similar principle in automatics when they change gear.

Now while the trans is new the gap between the band and the drum is small. This means there is a smoother action with little noise,..however, once the band's friction lining and to some extent the drum's surface wears (which gives rise to swarf in the trans pan) the time taken for the band to tighten around the drum increases *and* the band's speed increases due the extra gap before it contacts its drum. This causes the thump or jerk as the auto changes gear.

During trans servicing, these increased gaps are to some extent decreased by adjusmnts so the thump is reduced, however, other parts of the auto are also wearing including the internal oil-pump which provides the motivating force (oil-pressure) to apply the brake-band. So just because the band clearance to the drum has been returned to normal, the OP cant provide sufficient pressure in time. This causes slipping and that characteristic "wheeeup" noise in some autos.

The best thing is not to thrash the transmission which has high miles on it, as it just acceleraes more wear. The clutch=paks in autos suffer a similar fate as the brake-bands. Its important to ask the auto-servicing place if there was much metal in the oil-pan. The more there was, the greater need to go easy on the trans.

Jason

Ok, thanks for the detailed explanation.

I changed the tranny gasket and strainer about a month or two ago, didn't find a whole lot of metal, just some metal dust on the magnets...

Check kickdown cable adjustment.

Is this one in the Haynes manual? (I don't have a Haynes in front of me, and won't, until later this evening.)

Thanks,

Mike

Should be, it may be called "throttle cable" since it goes from the throttle to the transmission. IIRC, there is usually some confusion regarding "accelerator cable", "throttle cable" and "kickdown cable". The latter two are the same in many cases.

Thanks!

I'll also try and curb my urge to floor it. ;0

Mike

"hydraulically operated bands"? on mine (A140E) (4 cyl.) - there are multidisc clutches - didnt' see any bands (in the shop manual) shifting occurs when the valve body shifts hydraulic pressure to the various clutches to hold or release dont' remember exactly - some have 7 plates and discs, some 5 - IIRC

before you adjust the kickdown cable, adjust the accelerator cable for full open at wide open throttle (conc. block and 2x4 on gas pedal) There's less tension on the transmision cable, and if you adjust the accelerator cable first - it should follow along and be fine.

You know, that might just be it. It's not particularly jarring, it's just noticeable.

I had expected it to be as smooth as a part throttle upshift.

Sure is. Just changed the tranny strainer last month. I did two tranny drain-and-fills... that should get at least half of the tranny fluid changed...

I'll have to look into this.

Many thanks,

Mike

Yes, the correct term is "hydraulic servo", which is basically a piston operating in a bore with an attachment (in this case) to one end of the band. The other end of the band has an adjustment to take-up any wear.

Heres mention of it in a spare parts book.

Camry A140E L- p/n 81714 Band, 2nd Coast Camry 1983-On 4 Cyl FWD 4 Speed Transmission Code A140E or L Band, 2nd Coast 1983-On $33.55

With the exception of the "Hondamatic" transmission which is very like a manual transmission with servo-operation, all other automatics use epicyclic gear sets which include an outer ring-gear with 4 planetry gears and a central sun-gear. To effect more than 2 speeds, a second set of planetry gears and sun gear are used. The "brake-band" operates on the outer ring-gear drum.

Jason