Buongiorno, There was a thread on quicker smoother shifting on 3x8 gearboxes that I can't seem to find now. It referenced several oil/adjustment changes and also the "supercrunch" GM Muncie M22 trans. Back in the day, I blew-up/damaged/re-built my M22 about 9 times. I finally started using molybdinume disulfide additive (molylube, and don't comment on spelling) with excellent results in smoother, quiker shifts and syncro performance. I also used slick50 trans additive in a previous Toyota truck I owned with excellent results. Long story short, anyone have comment on positives,negatives, or experience with moly or slick50 type additives and Ferrari trans use? ?????? -Luigi
2nd gear or all thru the range? There is a design flaw on 2nd that can be remedied with some drilling/machining mods, IIRC.. I just loaded up the Royal Purple 75-90W...works good once it's warmed up.....
BE CAREFUL WITH GEARBOX LUBES AND ADDITIVES. MANY FRICTION MODIFIERS CONTAIN STRONG CHEMICALS THAT CAN ACT LIKE ACID. SOME WILL ACTUALLY BURN OR IRRITATE YOUR SKIN. NOT GOOD FOR SOME METALS. I WOULD STICK TO SATNDARD LUBES. I USE REDLINE, THEY WILL EVEN GIVE ADVICE OVER THE PHONE AND ARE AWARE OF THE 308 REQUIREMENTS. [email protected]
Did these things work any better when they were new? Did contemporary road tests complain about the shifting? As I get more familiar with this car it becomes more apparent what a flaw the shifting is.And the clutch effort as well. Tom
New clutch, resurfaced flywheel, fresh gear oil. There seem to frequent enough posts on this to make me think I'm not alone in wondering about this. I've been driving a 20 year old 911 that I'm working on that really highlights the less than stellar shifting of my 308.
When I bought my 308 back in 99 I had the same old issue with 2nd gear and in 2001 I drained and started using Mobile 1 straight out of the bottle. Seemed like it improved and would only have a little stiff gearbox during the winter (20-30*) days. So I changed it twice and each time I changed it the shifting got smoother. So this past winter I have been impressed that I didn't need to do the 1 to 3 shifting until the gearbox warmed up. So I don't know how this is working but things are good and I don't have the cold shift issue. But I still have a problem at times in downshifting into 2nd but usually double clutching usually solved the problem. So the net is I'm sticking with Mobile 1. Enjoy the ride.
See I have to disagree on this. I just sold my 911. It was an SC. The shifting was no where near as nice as my 308s. Once your 308 is setup properly it shifts great IMO. My 911 shifted ok but the 915 trans isn't known for great shifting. I have used various gear oils. I have used Mobil 1 syn. in my 78 for 7 years. It works great. Is your shifter adjusted properly? Once you get it setup properly I think you will be very pleased.
My observations on the whole shifting topic are somewhat in line with the postings, but go a bit further. I have found that the deterioration of shifting to be due to faulty bushings, and clutch problems, such as drag. The stock bushing at the rear of the shift linkage seems to be the worst offender, as it is usually badly in need of replacing after years of exposure to under the bonnet conditions. The stock shift gate on the console then becomes the limiting factor. If observed, the shift stalk will contact the end of the slot, as the shifter is moved. What is happening is the linkage, bushings, etc allow enough "give" so that the lever does not apply the necessary force to the shift mechanism to allow the synchros to do the job. Synchros need applied pressure to engage the conical surfaces that do the actual matching or syhcronization of the shaft speed. Worn shifter parts, combined with a limited travel cause there to be a less than satisfactory movement. A slight lenghtening of the slot will help, as will fresh bushings. A bit of fresh lube in the shifter base will make a nice differance as well. The design of the unitized motor/trans system is a part of the problem as well. Compare the differances in rotating weights between the 308, and standard rear wheel designs. The extended shaft, drop gears, etc add a lot of rotating inertia that must be overcome to match the gear speeds and provide a clean, smooth shift. That is a lot more to overcome than a typical OEM rear drive layout. Ad a dragging or stick clutch disc that doesn't release well, and it is a wonder they shift at all. Flame suit on.
I recommend SWEPCO 201. Not a synthetic. Available at Performance Products, Pelican Parts. Long been a favourite of Porsche racers. I have used it for years in my Porsche race cars and it stands up to heat very well. Also it is not too slipery (unlike Redline) which prevents the synchros from properly working. (Synchros work like little cone brakes). Has the additive required for clutch type limited slips already blended in. Put Swepco 201 in my '75 308 GT4 about a year ago. Works very well. Even allows me to shift from first to second with the motor and oil stone cold. Originally developed for heavy duty trucks. Martin Jansen
Kermit, The clutch is not the problem, I also believe the synchro's are OK because I don't have any grinding going up or down- it's all just too stiff. On center feels OK, but I was beginning to wonder if the linkage, particularly the shaft bushings, needed attention. I try that next. Thanks to all , Tom Redline gear oil is on order also. I also need 100 more horsepower.
Note Sloan83QV and others are recommending Redline 75w-90 "NS". The "NS" means "no slip" additives...so it will NOT be too slippery, and is just the ticket for a Ferrari transaxle.
Road & Track, May 1986 test on the then-new 328 confirmed that 2nd gear was unobtainable and shifts had "the consistency of moving a paddle through glue" until the gearbox warmed up. Translated into Italian and back again, this reads: "2nd gear is very rewarding and shifts are a constant pleasure at all temperatures."
http://www.mobil1.com/USA-English/MotorOil/Other_Products/Other_Products.aspx Doesn't appear to be any manny tranny oil here. Auto, rear axle, transfer case, yes.
