TKO600 3rd Gear Difficult

[StromSpeed]

I have a TKO600 in my build with a McLeod Clutch and Quicktime bell.
The TKO is brand new, about 200 miles on it now, and I have some difficulty getting from 2nd to 3rd gear with speed.
I initially started with the ATF fluid as specified and had problems going from 3rd to 4th. It was like a solid block. Thought this had to do with the syncros.
Then I switched over the RedLine MTL (exceeds GM Syncromesh fluid) and now the 3/4 is great. But now 2/3 is difficult; the warmer the fluid the more difficult it gets (fluid gets to 140F). So difficult that now it will grind :eek: regardless unless I let the RPMs drop below 4.5K, then it will go in without issue and a light hand. And yes, clutch is all the way in for the shift. No issues with other gears. Going from 3rd to 2nd is great, no problems no matter the RPM. Something is not correct as production manuals I could shift quickly without issue.

Internet search shows lots of complaints with this 2 to 3 shift on the TKO. Anyone have this issue recently?
I need to shift fast for racing purposes and this is killing my straightline speed waiting for the RPM drop and slow shift.

Any others have this issue? Solutions? :confused:

Thanks in advance.

[Avalanche325]

The ONLY thing you should be putting in there is GM Synchromesh!!! Not ATF. I have read of the same symptoms with other than Synchromesh. You also DO NOT want anything that "is the same as", "meets" or "Exceeds" GM Synchromesh specs (Like Pennzoil, RedLine, etc). You want actual, true, genuine, original, bona fide, GM Synchromesh.

Mine had a big red tag on it that stated Synchromesh.

[StromSpeed]

The ONLY thing you should be putting in there is GM Synchromesh!!! Not ATF. I have read of the same symptoms with other than Synchromesh. You also DO NOT want anything that "is the same as", "meets" or "Exceeds" GM Synchromesh specs (Like Pennzoil, RedLine, etc). You want actual, true, genuine, original, bona fide, GM Synchromesh.

Mine had a big red tag on it that stated Synchromesh.

OK, appreciate the feedback. I did not receive any tag on mine. The only paperwork it came with was to use D4 ATF!!
Again, quality control on packaging could be an issue in Mexico......

Best place to purchase that spec of fluid?

[Davidbr_48]

Question: There are at least two flavors of GM Synchromesh tx fluid -- one is labelled AC Delco and sells for ~$10/qt, the other is labelled GM Vehicle Care, is called Synchromesh Transmission Fluid and sells for ~$20/qt. Which is the right one?

tks - Davidbr / Tucson

[edwardb]

Question: There are at least two flavors of GM Synchromesh tx fluid -- one is labelled AC Delco and sells for ~$10/qt, the other is labelled GM Vehicle Care, is called Synchromesh Transmission Fluid and sells for ~$20/qt. Which is the right one?

tks - Davidbr / Tucson

The instructions that came with my TKO600 stated that GM Synchrosmesh should be used. The dealer where I bought it also said to only use genuine branded GM Synchromesh, not something labeled as equivalent, and that it would make a noticeable difference in the shifting if I used anything else. When I researched this a year or so ago, found the genuine stuff was labeled as AC Delco. Bought it from Summit, since I couldn't find it locally. Just saw this at Jegs. Best price I've seen: http://www.jegs.com/i/Chevrolet-Performance/809/88900333/10002/-1?parentProductId=3126449

[Kinge]

Our shifting has improved dramatically with use. Especially the first 1000 miles. I am glad I didn't spend a bunch of effort worrying about it at 200.
- not trying to discredit the fluid discussion!!!

Jeb

[Avalanche325]

At some point the labeling changed from GM Synchromesh to AC Delco Synchromesh. It could be the other way around.
Summit has it for $15.47 / qt.