NOT MUCH ,
3RD GEAR SWITCHING TO 4RD ABOVE 2100 RPM , THE TRANSMISSION SLIP BUT UNDER 2100 RPM IT GRABS FINE

ONLY HAPPENS ON UPHILLS AND HARD ACCELERATION , HELP PLEASE

 

If the transmission is slipping under load and there is the correct fluid level in the transmission(check the dipstick, level should be on the hash marks) then most likely the clutch pack for that gear is worn out. How many miles on the AT?

EDIT: Has the car been used for towing/hauling? 4th gear is usually only under light load during cruise, if the gear is wearing out prematurely its possible that the car was used for towing/hauling at freeway speeds. With most automatics, even trucks, OD is not used or recommended when hauling or towing heavy loads. It can cause pinging/detonation and/or wear out the OD gear.

 

216k on the accord extrange tho bc it only happens after 2100 rpm

 

I had a similar issue w/ my 97 CL https://honda-tech.com/forums/honda-accord-1990-2002-2/will-not-down-shift-engine-revs-red-line-2944268/. Replacement trans is being installed today. Listen to MAD_MIKE he seems to be the trans guru around here. I have learned a lot from his posts.

 

It's a higher load. You have reached the maximum capacity of what that gears clutch pack is now able to hold. 2100rpm, thats about 50-55MPH with a stock Accord transmission. I see that as when the load on the transmission in 4th begins to increase. ~45mph you can almost put put along all day with little throttle input, above that you encounter more wind resistance and requires more throttle input. If the clutch pack is unable to hold then it will begin to slip at, and above, 50mph.
You may want to check the shift solenoids. Possibly one is partially clogged not fully seating the pintle valve. http://techauto.awardspace.com/transmission.html

Jmb106jr I merely have just looked over posts, and learned from other members about the mystery box known as the Automatic in the Honda H/Fs. nus_dogg and phootbag should also be recognized for bringing the tech when it comes to the ATs.

 

MAD_MIKE, I know Phootbag is a Honda tech and has been very helpful in my tranny wow's. And i have seen many post by Nus_Dogg. Don't sell yourself short as the knowledge you have gained you freely share w/ the rest of us. Thanks. Joe

 

ok after doing diagnostic and test this is what i have found

when i shift manually from 1st to 2nd then to d3 ,d4 gears will grab and switch fine no slipping is feel would that have to do anything with the solenoids