Black TL

Hey guys,

My 99 TL's transmission (116k) continues to bang hard when shifting from 1st to 2nd and 3rd to 4th when cold. 1st to 2nd is relatively new (this season) and happens while accelerating, while 3rd to 4th happens more when i let off the gas when in 3rd and it falls into 4th (even at lower RPMs). If I give it a little gas when shifting from 3rd to 4th, i feel a bang but it's less noticeable. My front and rear motor mounts were replaced with OEM however the banging still persisted (rear was busted though so the replacement wasnt a complete waste). The side mount was fine when I pulled it out, so I left the old one in (have the new one sitting in the box). My two lower transmission mounts were fine (no cracks). i dont think we have an upper tranny mount so I haven't checked that. I also replaced the transmission fluid just a couple of weeks back with the new DW1 however it still bangs (and slips a little 2nd to 3rd.

While I know a solution is a transmission rebuild, I just need to know what causes the bang. From my understanding, a transmission is not supposed to bang (it's a hard bang for sure and I feel it on the floor/chasis). When the car is warmed up after a few miles of driving/shifting, it stops banging completely which is good, however with the weather getting colder here it's starting to bug me more since it takes longer to fully warm up.

Any ideas what physical part in the transmission can bang?

Thanks

acutee

More likely your engine mounts are cracked. There are 3 of them: front, rear, and side (where the belts are).

FwC

iTrader: (1)

Does it bang when you go from Park to Reverse and from Neutral to Drive?
I'm not sure about '99 but most of the second gen TL and CL have poor motor mounts and these are the symptoms of bad mounts.

If you open the hood, you should see the engine jerk pretty hard as you're doing these shifts.

Black TL

I replaced the front/rear mounts with OEM and the same day it was still banging. The side was fine when I took it out to replace it.

It doesnt bang from R to D but it does when going into R from P or D.

fsttyms1

There are 2 trans mounts as well. I would look at them and see if they are torn or in need of replacement. The other thing i would do is pull out the shift solenoids and either replace them or clean them and see if that helps. (and the most likely cause of your issues)

3.2TLc

Hey BlackTL, once you've made sure that all of the motor and tranny mounts are good, then if it's been awhile.....perform a drain & fill with genuine Honda fluid. Replace the filter, clean the solenoids, check that all electrical connections, vac, and grounds are secure for the tranny.

Shifting problems within an electronically controlled tranny can very well be mechanical in nature. There is a PCM for the system that is down underdash behind the console. If you're getting a CEL or flashing D4....there could be a problem. The PCM can be checked by a scanner for error codes that may be stored.

01tl4tl

if only people would read what the OP has done so far,,,,,

double ck fluid level warm 15 minute freeway cruise as between the dots
perform mechanical torsion test on rubber mounts--visual not enough

do as fsttyms1 says

RC99TL

Exactly what mine did when the trans went at near the same miles.
You can try replacing the pressure switches but it is most likely fluid pressure bleeding off at low rpm/cold conditions causing a delay to the clutches on the gears packs.
My dealer could not replicate the issue so I asked him to take the car home and see if it did it in the morning. It did and I got a new trans at 98k and 7 years old.
When warm it was perfect. So try replacing the pressure switches and another fluid change. The banging will wipe out the motor mounts real fast as well so before you wind up needing another set try the switches, they are an easy fix.

Black TL

Thanks guys. My lower transmission mounts can be seen in this vid at around the 2 minute mark. They look okay to me but you're better experts than I am:


The transmission fluid was bright pink and right at the center so the level seems okay.

I haven't checked the pressure switches or cleaned the solenoid screens. The screens look like they're a pain to get out and I might not have the tools to do so. I see there are two pressure switches and the solenoid which has the screens. What gears do these affect? Also, If I remove them, will my transmission fluid spill out?

Thanks again!

01tl4tl

fluid level was ckd with the 15 minute freeway drive from cold method?

rubber mounts are tested with a prybar (didnt watch video)

see the diy section for tools and pics-tips on the selenoid screens
its not that bad,,compared to buying a trans!!