Problems with the 307

I have had just little problems that are starting to add up.
Engine idle at a stop light from slightly fast to just right to too slow
Sometimes downshifting coming to a light. Seems to hang in third, and then at last minute will do the 3-2 and finally the 2-1.
Last night for the first time it shuddered when up shifting at about 15mph or so.
Trans oil appears clean and clear changed at 14,000 or so, now showing 37,000 miles.
Thought it might be a solenoid, or a front mount, part number 25511570 as I have heard they do go bad.

Am looking for ideas as to how to proceed at this point.

IDea:

1) how long did it take to rack up the 20,000 miles since your last trans fluid change? If less than 2 yrs consider changing it again.

2) check your fuel (carb/throttle body) intake system. You may need a carb cleaning - could be that the downshifting is delayed because the engine is revving too fast w/o throttle.

3) no reason not to check the mounts, would be nice to have someone who's seen a bunch of them look at yours and comment.

Albertj

I'm confused... 307? Carb? Are we talking about a late-model Riv, or an old Chevy with a 307?

I seldom disagree with Albert, but I would say that the longer it takes to rack up the miles, the more often you should change the fluid, regardless of the which car. Fast runup of miles generally means lots of highway running, which is easier on both the engine and tranny. Slow accumulation usually means lots of city driving, with lots more shifting, etc...

In either case, you're getting near my personal 30,000-mile limit, and probably should have the tranny fluid changed.

I believe "Straighteight" is refering to the Olds manufactured 307 ci that was in the early '80's to '85 Rivieras (he posted also on the ROA section of the AACA forum).

Thanks for your responses. Do you reccomend GM or NAPA for replacements?

GM..

Ship wrote:

I believe "Straighteight" is refering to the Olds manufactured 307 ci that was in the early '80's to '85 Rivieras (he posted also on the ROA section of the AACA forum).

Thanks for the clarification, Ship.

Someone needs to fill out his signature file... hint, hint

Well I guess we can close this out. Think I found the trouble. I replaced the TCC, and filled with fresh fluid, new filter and gasket.
She runs great. I was unable to come up with GM parts and had to go to NAPA got an Echlin switch and NAPA filter and gasket. Parts seemed fresh as contrasted with GM parts that had been drying out on the shelf.

Eldo would like me to fill out my signature file, so would I, Just can't seem to get my info to show. It ain't much. The 98 pictured is stock, and low mileage. The 85 is also stock and low mileage.