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Discussion Starter #1
I took a chance on a used TKO 600 that someone had in their mustang. He said it only had about 5000 miles on it. He did race the car but said he never had a problem with it. He wanted to change to an auto for more consistent times. I've had it in my car now for about 1200 miles. It seemed to be fine. Normal TKO quirks. At about 1100 miles it started to give me trouble down shifting into 2nd about 50% of the time. Its hard to go in and makes a dull growl. Shifts fine other than that. I have searched but cant find anything about this specific issue. I have a quicktime bell housing that was dialed in. Actually it went right on and was with in the tolerance. Center force clutch with Mike Forte's hydraulic set up. My first plan is to check the clutch adjustment on Thursday. I just don't see that as being the issue since all other shifts are fine. I did clean it out and inspect it when I got it. It all looked good then. I didn't notice any worn gears or syncros at that time.

Anyone have any ideas?

Thanks,
Tony
 

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What trans lube are you running? I have heard some improvement in shifting using GM Syncromesh. If you are not already running it, it will be the easiest correction attempt, I can think of.
If the issue is with cold start only or hot only, the fluid might help. Might also check clutch adjustment.
 

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Discussion Starter #3
What trans lube are you running? I have heard some improvement in shifting using GM Syncromesh. If you are not already running it, it will be the easiest correction attempt, I can think of.
If the issue is with cold start only or hot only, the fluid might help. Might also check clutch adjustment.
I am using the GM Syncromesh. Yesterday on a cruise after it was hot is when it started. Haven't driven it since. Plan on checking adjustment Thursday and giving it a test drive.
 

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Agree about the Genuine GM Sycromesh already mentioned. I've found that can help. Clutch adjustment is certainly another thing to check. Also make sure you're always pushing the clutch all the way down. Sometimes I'll get lazy and realize I'm not pushing it in far enough. But having trouble in one gear is a little concerning. In the TKO, 1st and 2nd share the same syncro. Probably you would notice 2nd being an issue before 1st. One thing you can try, and could help to identify if it is the syncro, is double clutching. Release the clutch when you're in neutral. Then push it again before shifting to 2nd. If it goes in easier or without growling (as you said) that would suggest the syncro isn't doing its job. I had a T-5 that also didn't like going into 2nd, and this confirmed it was a worn syncro.
 

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Discussion Starter #7
Agree about the Genuine GM Sycromesh already mentioned. I've found that can help. Clutch adjustment is certainly another thing to check. Also make sure you're always pushing the clutch all the way down. Sometimes I'll get lazy and realize I'm not pushing it in far enough. But having trouble in one gear is a little concerning. In the TKO, 1st and 2nd share the same syncro. Probably you would notice 2nd being an issue before 1st. One thing you can try, and could help to identify if it is the syncro, is double clutching. Release the clutch when you're in neutral. Then push it again before shifting to 2nd. If it goes in easier or without growling (as you said) that would suggest the syncro isn't doing its job. I had a T-5 that also didn't like going into 2nd, and this confirmed it was a worn syncro.
Thanks Ed. If the adjustment is ok I'll try the double clutching idea. My fear is it's the syncro. Crossed fingers on adjustment. I really don't want to pull this thing out.
 

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Hi Tony,
If you have any questions about clutch adjustment please feel free to call for tech advise.
 

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If you are double clutch downshifting from third to second, you will need to rev match when the clutch is out, trans in neutral between three and two when you double clutch. This will get the input shaft and second gear rotating close to the same speed so the synchro won't need to do much work.
 

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Discussion Starter #10
I gave Mike a call today and followed his advise on clutch adjustment. I did need a bit more free play in the slave cylinder. I had about 1/16 and he recommends 3/16". This just keeps the throw out bearing from ridding on the clutch fingers. Some people say you need no free play and others say you do. It had plenty of clutch travel. I could depress the pedal and turn the drive shaft by hand. After that I still had at least another 1/4" slave cylinder travel when I pushed the pedal to the floor. (didn't have a helper or I would have taken an exact measurement). I then went for a test drive. At first it seemed like normal. Once it started getting warm, it felt and sounded slightly different going from 3rd to 2nd. Nothing like it was doing on Saturday. But Saturday was probably the longest drive so far with it. (It might have gotten hotter than it ever has). I had the tunnel cover off today which allowed me to hear more. I could hear a slight gravely noisy only after down shifting into second and only after it started getting warm. (It wasn't horrible but it also wasn't good). When I get a chance to go for an all day cruise again I'll see what happens. If it regularly acts up I'll try the double clutching idea. But I'm leaning towards it being a trans problem anyways as of now.
 

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Double clutching downshifts is fine. I enjoy it. But you should not have to do it w/ a modern trans.
 

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If you are double clutch downshifting from third to second, you will need to rev match when the clutch is out, trans in neutral between three and two when you double clutch. This will get the input shaft and second gear rotating close to the same speed so the synchro won't need to do much work.
Double clutching downshifts is fine. I enjoy it. But you should not have to do it w/ a modern trans.
Just to be clear, I wasn't suggesting this as a permanent fix. I only suggested it as a troubleshooting step. If double clutching (including the rev match which is the main idea) allows it to go into gear more easily without grinding, etc. then that's a pretty good sign the issue is with the syncros. If so, I'd get it fixed.
 

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Discussion Starter #13
Just to be clear, I wasn't suggesting this as a permanent fix. I only suggested it as a troubleshooting step. If double clutching (including the rev match which is the main idea) allows it to go into gear more easily without grinding, etc. then that's a pretty good sign the issue is with the syncros. If so, I'd get it fixed.
Yes, I completely agree with you. If it acts up again and I can test it, I would know for sure its a syncro problem. I would then fix it. Most likely have Liberty or someone like them work it over to make it a smother transmission. Getting ready to call them now.

Thanks guys.
 

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I gotta ask cause maybe I'm just not understanding? Are you downshifting into every gear to decelerate? If so, stop. Down shifting like that and braking at the same time, in one of these cars, will bring the back end of the car around quicker than I can type it.
 

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Discussion Starter #15
I gotta ask cause maybe I'm just not understanding? Are you downshifting into every gear to decelerate? If so, stop. Down shifting like that and braking at the same time, in one of these cars, will bring the back end of the car around quicker than I can type it.
No, I generally don't down shift to decelerate. Especially if its a quick deceleration. I might do it some if I'm coming to a long slow stop.

Maybe my speed has slowed and I need to drop a gear. Or maybe I've come to a stop or coming to a stop with the clutch in. I run the gears down to get to first to take back off. I never go from say 4th to 1st without stepping back down. 4th-3rd-2nd then to 1st.
 

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Here is another kind of contrarian thought on trans oil. Over the years I have on several occasions w/ different cars made changes to the standard recommended oil. One was fine in the summer but a bear to shift in the winter. Spec was a 75-80 oil. I ended up using 50% 75-80 and 50% 30W engine oil in the winter. Another car we put in what was the latest hot idea on trans lube. It lubed too well. The synchros didn't work well enough and we got some grinding on anything faster than a granny shift. Out came the latest hot idea oil. More currently in my MkII FFR TKO 500 I have religiously used the GM Synchromesh oil. But last summer I started getting a bit of grinding on a quick 1-2 upshift. Hey 40,000 miles and many, many autocrosses, I figured the syncho was wearing some. Not real interested in rebuilding the trans so I drained a qt or so out, and topped up w/ 30W engine oil. Problem fixed. My point is that there can be some variance in both oil thickness and oil slipperyness (technical term) and one can deviate from the specified oil to help solve some trans problems. It may not always work, but compared to any trans repair, trying a different oil is a dirt cheap experiment.
 

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No, I generally don't down shift to decelerate. Especially if its a quick deceleration. I might do it some if I'm coming to a long slow stop.

4th-3rd-2nd then to 1st.
Again, I guess I not understanding. The first sentence contradicts the first. You say you don't down-shift to decelerate then say you downshift 4th to 3rd to second and then to 1st. I think this is the problem. If you're in 5th coming of the highway, downshift to 4th until the motor starts to bog while braking to a stop. Call me old-school but I don't sit at stop lights with the clutch pedal pushed down either.
 
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