QuestionQUESTION: Howard, My 1979 TR7 (which I purchased a month ago) is having difficulty shifting into 1st or 2nd gear when the engine/transmission is warm. From a cold start the engine shifts very smoothly in all gears. The car also has difficulty shifting in reverse, and it is near impossible when cold. It's almost as if the clutch stays engaged when the engine is warm, but not when cold. What suggestions do you have to trouble shoot this issue?
Thank you!
Vito
ANSWER: Hi Vito,
First you should check the feel of the clutch pedal. Meaning is there only about an inch of free travel in the pedal and from there on down the pedal is firm and no extra carpet under the pedal.
Next it is very important that the RPM be below 1000 RPM at idle and that you do NOT try to shift from neutral into any gear for several seconds after the clutch is depressed. This is necessary to allow the clutch disk and first motion shaft and ALL gears to cost down to a stop before trying to put it in any gear from neutral.
You made a statement that I don't understand. you said "From a cold start you can shift ALL gears" but then you say when cold you can't shift into reverse. Which is it?
If all the above is followed exactly as I said, and there is still a difficulty in shifting into a gear from neutral do this,
When cold put the car on a smooth level surface and with the brake off, put the car in first gear and depress the clutch pedal all the way to the floor and start the engine and note if the car tries to creep forward.
Then repeat the same test after you have driven for a while to heat up the clutch and gearbox.
Let me know the results and in the mean time read my tech tips on gearboxes on my web site.
http:mg-tri-jag.net/tech4.htm
Howard
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QUESTION: Howard,
Thank you for the quick and detailed response. I can already give you some feedback on your text to see if it sheds any new light, and have new information.
The pedal is firm after the first inch. There is definately no extra carpet under it when depressed as it needs to go to the floor. I also am sure to be a a complete stop, at idle, and wait to shift before going into reverse or first.
I should have said "when cold I can shift cleanly into all FORWARD gears." It is very smooth from neutral to 1st, then 2nd etc as well as back down.
I conducted the test you described last weekend. When cold, with the car in 1st or reverse and clutch fully depressed, car will not creep. When warm, the car will creep once I take my foot off the service brake - more so in reverse than in 1st, but it does it in both directions.
new information: A frind of mine who knows a bit about triumphs happend to stop by just after I sent my first note. He thought the slave cylinder might be leaking, so he came out to take a look. No leaks, but the fluid in the cylinder was absolutely clear, very thin, and no odor. It actually DRIED very quickly on our fingers and did not leave any residue. He was very surprised and suggested I suck the fluid out and replace it with GM brake fluid. Your thoughts?
I will review your gearbox website. I sincerely appreciate the help!
Thank you!
Vito
ANSWER: Hi Vito,
I can't comment on the GM fluid as I never used it before. All brake fluid is rated as a DOT # and I always recommend DOT 4 fluid. All fluids can not be compressed however I would have been suspicious of the fluid in there too but unless you see leakage it may have been ok. There can be internal leakage in the master cylinder that can cause a problem and that is tested by putting the car in gear, engine running and sit in one place, holding the brake very lightly, just enough to stop the car from creeping and sit like that for a minute or so and note if it takes more brake to hold the car from creeping as you sit there. If it does that is an indication that the master cylinder is leaking internally.
The causes of clutch dragging (besides hydraulics)are a warped clutch disk, a warped clutch spring (diaphragm type)or a bad pilot bearing. It is also possible that the one of the two ears on the clutch release fork is badly worn or damaged.
In the dealership we had to make a decision on such as your clutch problem as to the hydraulic system or internal. And the standard method we used was the pedal feel both warm engine and cold engine and was it creeping on flat ground. If the pedal feel was good all the time then it was an internal problem and we would only do the job if we could replace the disk, pressure plate, release bearing and the pilot bearing all as a package and the only optional parts were the ears on the fork. Sometimes the pins that the small blocks are on mounted on the release fork were worn and then we replaced the clutch fork too. On a very few I found a rusted spline on the first motion shaft which made the disk not slid away from the flywheel when the pressure plate was released.
I replaced many clutch disks alone just after a customer replaced everything himself because he warped the disk trying to install the transmission onto the engine and was rough doing it and he warped the disk with the transmission first motion shaft. Either because he didn't use a clutch aligning tool or he was just rough and forced the engine and trans together. So take great care that they slid together smoothly when reassembling.
Good luck and let me know how you do.
Howard
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QUESTION: Howard,
Sorry for being a pest, but I wanted to give you and update and ask an opinion.
I "sucked" out the fluid in the master reservoir (using a syringe)... what I found was a top "layer" of clear/thin fluid (appeared to be comparable to DOT 3 brake fluid). Below this layer was a thick/black "goo".
In my opinion, this indicates there is a problem with the master/slave leaking and the prior owner just topped it off. My thought is I need to remove/clean/reseal both the master and slave cylinders.
I really don't want to even drive the car now as I am afraid to damage the transmission. I also noticed when the engine is running, the car in gear, and clutch depressed, it sounds and feels like the clutch is "slightly" engaged and causing gears to spin.
What are your thoughts. Regardless of the condition of the clutch disk I feel like I need a clean and reseal of the hydraulic system. Have you seen anything like this before? If so, what action did you take?
Thank you!
Vito
AnswerVito, knowing there was something in there that did not mix, I would do as you said and remove both and clean them out and remove the pistons and put a seal kit in both. Be sure to inspect the bores for pits as any pits can shortly destroy the new seals.
As for gears turning when the clutch is out and it is in neutral, all the gears in the gearbox are spinning. When the clutch is depressed no gear is turning (unless you have a dragging clutch or you are moving) If you hear a noise when you depress the clutch pedal it is most likely a release bearing going out.
Howard
