308 GT4 gearbox issue

Hi all.
First off..... Hello. New poster to the forum but have been reading and enjoying it for a long time.
My car is a 1977 Dino 308 GT4 chassis number 13076 UK RHD.
I picked up the car in October 2018 as a private sale with a few issues that I was aware of that needed attention. Suspension, Various trim items and...... gearbox. It drives well and has a strong engine and after 16 months of getting to know it, its time to start fixing!

The gearbox had a full rebuild in March 2012 and less than 1000 miles ago. When I test drove the car, I found it hard to get 2nd into position regardless of temperature and revs - it was like there was a mechanical barrier. It didn't grind unless tried at higher RPM (which I didn't do more than a couple of times) it just didn't want to move into position . After speaking to a well regarded local garage, they suggested that I need the linkage and shifter aligning which they did by removing the sump and making adjustments. This did indeed work, the shifter being more centralised in the cabin and 2nd being selected more easily. However, now it became apparent that 2nd would only select cleanly below 2k RPM. Anything over this, and it would grind in with a mechanical clatter. The garage who did the alignment work said that basically 2nd gear synchro is stuffed and needs changing..... that means engine out first and full gearbox strip down with huge expense.
I am surprised this is the case as the gearbox was rebuilt less than 1000 miles ago with all new synchros and lots more, and yes I realise I have no idea how the car was driven between then and when I purchased it, but I would have hoped that the Syncho would have lasted longer.
I have tried changing the oil to the highly regarded Redline 75W90NS in order to help the Syncho. I realise this is not the right oil for the Diff, but I thought it would at least highlight if the Synchro was salvageable. It made no difference.
So my question is...... Is it possible to inspect the condition of the gearbox and specifically the syncho whilst the gearbox is still in the car. Can you remove the sump and visually check the 2nd gear action and see if there are teeth missing? The oil change I did showed nice golden clean oil without much metallic material and no lumps of teeth.
Also, I did read on this forum somewhere that it is technically possible to work on the gearbox whilst it is still in the car. Is there anything you think I could try to replace, improve or test the gearbox whilst its still in place?
I know if I take the engine out I will be opening up a whole can of 'might as well change it' worms like doing the sodium valves, bla bla.....
Any advice or comments would be welcome.


Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login

 

The degree of wear can be determined by removing the pan but it will be impossible to determine if the surfaces are glazed which can cause your condition. If indeed the syncro really was replaced it is hard for me to believe it is worn out. In cases of incorrect lubricants being used I have seen the functioning surfaces get glazed which inhibits proper syncro action. Also since the gear and the syncro are iron materials gears wear too. I have seen new syncros put on worn gears which prevent good operation. That also can be determined without removing the transmission. I'd suggest trying Redline MT90 or MTL first. Nothing to lose. If that does not work you will probably be pulling it out. If it is an issue of glazing of the surfaces it can be corrected by lapping the gear and syncro as you would an engine valve but you need them in your hands for that. I do that when I replace syncros anyway. It makes them shift better.

 

Thanks for your reply Rifledriver.
So with the sump off, would you be able to get your fingers over the gear that the 2nd gear syncro is struggling to engage with? Forexample, would you be able to feed some 1500 wet'n'dry over the gear surface to lightly work it and reduce some of the glazing? Or is that area of the gearbox out of reach when just removing the sump?
If I could get to it to improve it slightly by doing this, I would then have some confidence that the issue is not the syncro itself.
I just don't like the idea of giving it to a garage to recondition who will simply replace everything for safety sake when its not really needed.

 

As I said, it can be evaluated to a degree with the pan off. It can only be fixed by taking it apart.

Please reread my first post at face value and not read things into it.

 

Tom, I’m in London and sometimes come down to Edenbridge to check on my 308. I can help you have a look if you get it up and the pan off (don’t lose the springs and balls when the pan comes off.) It’s easy to check the synchro wear— check link below. I have all the tools if it needs to come apart. Who did the work?
https://www.ferrarichat.com/forum/threads/dereks-308-engine-rebuild.535247/page-13

 

As owners we are very lucky in the South East of the UK in that we have a multitude of good, experienced and honest Indy repairers who you could trust to sort this for you. You could take this to QV, Autofficina, Barkaway and others and know that they will deal with this as reasonably as it can be dealt with

 

Yep I should talk it through with a couple of those also. The place I did take it to put the fear up me with a £7k to £10k estimate for engine out and full GB rebuild costs even after sight of my past invoices for the recent GB rebuild. I'll give them a call tomorrow. Autofficina looks closest to me, but read good things about Barkaways in Enzo magazine few issues back.

 

Thanks Derek, that's really helpful. Great rebuild thread. SMDG did the recent alignment work. Rardleys did the rebuild work back in 2012

 

I have a close sister to your car which I've owned since 1985. It lived up the road in West Byfleet for many years.

I've been using Amsoil gearbox oil in mine since the gearbox was rebuilt many years ago. The gearbox is still as nice as it's ever been and much better than it was when I bought the car when it had apparently already had some gearbox work done. The car is quite usable without second, but not when you only have first and reverse (don't ask me how I know).

Bills of £7-10K are sadly pretty normal for these cars today. In the old days everything was £2K, but £2K just doesn't buy you what it used to!

I don't know what history you have with your car but if you haven't owned it for long, you never quite know what's been done or how it's been treated. It would be surprising if the sodium valves haven't already been replaced and the camshaft drive sprockets changed, but if they haven't you should definitely consider getting them done as failure will result in a large bill and an unusable car.

Sounds like a generous offer from Derek and at least then you will know what direction you need to go in. Congratulations on the car and have fun with it!