308GT4 Technical Questions

Hello,
I’m working on a 308GT4 that is unfamiliar to me. I got the car running and brought it up to temperature. As I tried the car under its own power, the clutch and gear box felt fine. Clutch engagement was good, however I have no 1st gear. The reverse lock out works good and the gear engages fine. 2nd, 3rd, 4th, and 5th all engage and drive fine. When I go to the first gear position there is no resistance at all, it just goes to the bottom of the gate with zero mechanical feel. It feels as though there is no shift rod, or synchro resistance. Does first gear have its own shift rod? Is the fork in the gearbox paired with the reverse gear? Could this just be a symptom of some misadjusted linkage? Any advice on where to begin would be helpful.

Secondly the top of the coolant tank in the engine bay has a pin hole that was shooting up a tiny stream when under pressure. My basic question is, can the tank be removed from the top side or is there a special procedure for removing the tank. My plan is to braise the whole and refurbish the tank in general. Any special draining procedure? Thanks for the help. Steve

 

First and reverse are on the same fork. You can drain the transmission oil, remove the pan and see what is happening. Might just be misalignment but seems like you would also have trouble with 3rd and 5th.


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From memory the expansion tank went in by removing the fiberglass air intake duct and sliding in from the front opening rather than out of the top of the engine bay.


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Thanks for the info thus far. The coolant tank removal is very straight forward, and I just mis-read the shape of the tank, lots of black in that corner! I have watched some helpful gear selector videos and it seems that reverse and first is on the same fork. Then 2nd and 3rd and finally 4th and fifth. Looks like there is a number of adjustment procedures for the shift rod it’s self, in order to center the shifter in the neutral position, and to ensure the shifter doesn’t go too far forward or backward in the gate slots. Secondly there is an adjustment in the gearbox after the sump plate is removed that allows the fork selector to be rotated to gain even more adjustment. I’m wondering if the external rod adjustments should be performed prior to the internal adjustments. In other words, could doing the external adjustment solve the issue with needing to get into the gearbox?

 

Remove the wheel liner to get to the hoses on the tank from the back. There is also a nut back there. I think 10mil. My liner was out at the time so that’s how o reached in.

 

To adjust the shifter properly I believe you need to do both adjustments. There is a threaded rod in the shift shaft that is external to the gearbox. The internal adjustment is not as bad as it sounds. Just need to order a new gasket and be prepared to catch the lockout springs and ball bearings on the drivers side. Treat yourself to fresh redline MTL while you are at it. You won’t regret it.


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Hi,

The reverse and 1st are indeed on the same fork, but reverse does not have the synchro assembly. From the description, it seems that it could be a problem with the slider assembly or the synchro hub on first gear. I would also suggest to begin by draining the gearbox oil (rearmost plug) and removing the pan. Hopefully, it is only the fork that is slipping in one direction (first) and catching on something on the shaft when engaging reverse. Removing the pan also makes adjusting the linkages a breeze.

Concerning the overflow tank, I had a similar problem and tried a similar solution (brazing and refurbishing the tank). After I had done all that, I realised that it was just waiting to leak from another place since it's all corroded on the inside. As Rifledriver said at the time, these are consumables. He was right...

Good luck,

 

Thanks guys. I noticed today that the first gear gate was very worn, almost to a point. By forcing the shifter to the right it felt like it engaged first today, but I wasn’t running it because I was working the expansion tank issue. I think it will likely come down to doing the linkage adjustment procedure and establishing a solid baseline setting for all the shifter settings. The expansion tank does have about 4 pinholes that I found while bead blasting the tank. The tank seems worth saving so I’ll rework it. I love to save original parts if possible. I really appreciate all the advice so far, it very helpful.