Intermittent inability to shift from 1st to 2nd gear at low speeds (manual tranny)

[datsa]

I've noticed increasing difficulty of shifting from first to second gear with my manual transmission.
This is not a constant problem, but happens intermittently, although with increasing frequency starting this morning. When this does happen, I can shift from 1st to neutral, but then it feels like I am hitting a blockage when shifting from neutral into 2nd gear. If I drive it a bit, then I can shift from 1st to 2nd fine; but later, the problem occurs again.

Occasionally I've had problems shifting from 2nd into 3rd, but I can easily shift from 2nd to 4th. But this has been a rare occurrence.

Shifting to the other gears are fine.

Shifting between the gears while the engine is off and the clutch is in seems fine.

There is no grinding or trashing of gears as far as I can hear. Rather, when the car is moving (and only when the car is moving), I press the clutch down, move the shifter from 1st to 2nd, but it stops in neutral and won't go into 2nd gear. If I coast a bit, or wait a bit, it will then go into 2nd, but since waiting can be dangerous if you are trying to merge into traffic, I will rev the engine to enter 3rd or 4th. For some reason, I can enter 4th gear at a lower speed than I can enter 3rd gear. If I try to enter 3rd gear at too low of a speed, I hear a grinding or thrashing of gears colliding.

But I do feel a "pop" and sometimes hear a hear a pop noise once I go into 2nd on some occasions. I had heard and felt similar sounds in the past, but it was very rare, perhaps once every few months. Now, I can feel it and hear it every time.

The clutch pedal travel distance does appear to be not as "tight" as it used to be. I am looking to adjusting this.

There appears to be sufficient clutch fluid in the reservoir and there are no leaks.

The clutch pressure plate and related parts are relatively new, about 3 years old; the original clutch died at 203,000 miles. The work was done by somebody else and not me (I didn't have time nor the expertise to do it, but I would not mind doing it myself: just no time to take on such a large project myself and I've never done a transmission before).
The only service that I have had done on the transmission is a drain and refill at the time of the clutch work. There are no transmission leaks that I can see and the fluid level in the transaxle (in my car the front differential and transaxle are in one case and transmission bathes them both; in automatics, they are separate) seems okay.

I am considering draining the transaxle fluid, looking at the condition of what comes out, then popping off the end cap of the transmission and seeing if there is gunk inside, and refilling the transmission case with something like Amsoil 75W-90 or maybe Redline MT90 which seems to a favorite here. I think there is regular SAE 90 in there right now.

Some of the causes which I am considering are:
* synchronizer not working
* shifter linkage
* manual fluid level
* clutch reservoir leakage
* shift fork not engaging
* internal transmission damage

What do you think?

[eage8]

I didn't read the whole posts because it's long haha, but I would try changing fluid and see if that works.

Also check your rubber shifter linkage bushings where they connect to the trans. one of mine was bad and it made shifting weird.

[datsa]

Well, yesterday, I did three things to the car:

1) I checked for damage to the shifter linkages and their bushings, but found no damage, but they were sure dirty and oily. The oil appears to be coming from a previous oil leak through the distributor, since fixed by replacing the O-ring and other gaskets (I got the distributor fix-it kit for 4AFE from Kbox of Canada).

2) I lubricated the shifter linkages inside the engine bay with silicone lubricant spray, including the rubber bellows. I also cleaned off any oil that were on the linkages; the oil came from a distributor leak, which has since diminished greatly since I installed a new distributor O-ring and ran Auto-Rx through the system.

3) I checked the clutch fluid level; it seemed a bit low, so I put in a small amount.

I had to get the car smogged. On the drive to the smog place, the transmission still experienced the 1st to 2nd shifting problem. (The car did pass smog with flying colors, better than any results in recent memory.)

But, mysteriously as of today the 1st-gear-to-2nd-gear shifting problem has greatly diminished, almost gone away.

I have not had time to change neither the clutch fluid, transaxle fluid nor the rear differential fluid. For the latter fluids, I was confused about whether I should stick with API GL5 for the transaxle (since the manual transaxle has synchros and GL5 is supposed to be bad for that but is required by the hypoid gears in both the manual transaxle and the rear differential)
or if I should go with API GL4, which is better on the synchros but does not have the high pressure resistance that GL5 does. I called up Red Line Oil and Amsoil and both said that I should stick with GL5 due to the presence of the hypoid gears in both differentials, despite its negative effects on the brass and copper synchros. Amsoil 75W-90 appears to be better for brass and copper than Red Line 75W-90, but Red Line has a 75W-90NS for that.

I look into this here or post a question about that . . . and then change all those fluids. It is easier for me to do all of them at once than piecemeal.

[Sturdavj]

Great stuff, try some, you'll like it

Lucas Transmission Fix


works on manuals