My theory of why 5 gear gard have tough 2nd gears when cold...

The first, second and third gears are fixed to the mainshaft and revolve at the speed of the clutch. 4th and 5th are fixed on the layshaft and rotate at the speed of the differential/wheels.

So in the case of the 1st, 2nd, and 3rd, the synchros are trying to match the speed of the mainshaft to that of the layshaft. The mainshaft is the constant as the wheels are stuck on the ground, the layshaft is the variable as it is connected to the clutch disk. 1st shares a synchro with reverse, and 2nd and 3rd share a synchro.

The ratios between the gears differ so there is a gradual reduction between engine and wheel RPM, from about 12.5:1 to a final drive of 3.4:1. The difference in RPM between 1st and 2nd is 4.4 RPM, then from 2nd to 3rd is 2.8, 3rd to 4th 1.4 and 4th to 5th 0.9. This means that the synchro between 1st and second is "working harder" by about 2x that of the synchro between 2nd and third. This "working harder" means having to overcome that much more rotational momentum.

So, in a cold box, the oil is more viscous, sticky and less willing to get out of the way in small spaces. This means the most stressed synchro (that between 1st and second) has to overcome an increased resistance of all the rotating parts on the main shaft (think of all bearings and mating surfaces), and deal with having to squeeze the thicker oil from between the conical mating faces of the synchro. Add these to its already tough job and you'll quickly see why the 2nd gear is the most likely synchro of all to want to resist the engagement in this condition.

This also explains why RedLine Superlight Shockproof helps the shifts. It is of a lower viscosity when cold as the standard 75W90 is when hot, so flows faster, meaning there is less stickiness in the rotating parts and can get out of the synchros faster. It lubricates using microscopic particles, that are about 3-9x thicker than a coiled oil (multigrade oils use molecular coiling to increase warm temperature viscosity while using a lower weight base stock for cold performance) molecule thereby provide about that much more resistance to shear (the resistance to falling apart when the molecules are squashed between metal faces). These particles are fully suspended in the fluid so there is no danger of them collecting and are in their biggest size still infinitesimally small that 100,000's of them can pass through the smallest lubrication pores.

Of course you could lubricate with automatic transmission fluid, getting the same benefits in terms of shiftability and corrosion protection, but it would be way too thin to sustain enough film protect against wear.

Ferrari always has adopted a wide gap between 1st and 2nd in most 5 gear cars, to ensure getting the thing quick off the mark and when shifting at peak HP, just short of the redline, it would drop the engine at peak torque for the 2nd gear. In 6 gear cars the jump is less pronounced and wider overall. A pedigree of racing, where once off the grid, 2nd became 1st, and you always staid in the "H" between 2nd, and 5th.

If you can add to this, go ahead, I just want to crack the myth of the "second gear when cold" and do so while believing it was done for performance purposes as opposed to poor engineering.


What do you say?

 

Why is it, base on your theory, that it's easier to shift from 1st to third bypassing the 2nd gear even when cold? I would assume that the conditions are even worse in that senario.

Ace

 

My question precisely. Based on the theory, getting out of 1st at all should be pretty much impossible while cold.

Sorry, but I don't thnk the theory matches observable data.

 

It's a blind hole the 2nd gear shaft slides into that provides no outlet for the fluid to pass when it's cold and thick.

I had mine drilled.

Here's the picture:
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BTW: In the 308 gearbox, ALL of the gears move when the engine is running, even in neutral. That's why it's SO IMPORTANT to make sure your entire engine INCLUDING the gearbox is completely warmed-up before you rev your engine to high RPM's.

It is also (and sadly) why so many gearboxes have worn gears. Many people mistakenly believe that many of the gears the gearbox are stationary when it's in neurtral, and that's just simply not the case.

Brian? Eric? Phil? Anyone else kind enough to comment on the veracity of what I'm saying and/or my unique position to comment on this very particular issue, please feel free to chime-in anytime.

 

So is the Redline Superlight Shock Proof one of the remedy?

 

I have never seen that make a difference in a trans that works well to start with. Personally even though it does not hurt I always felt it was a fix for a non existant problem.

 

Well, I had my doubts about that too, because of the way the shafts move. It seemed to me that it was the other shaft that would have an issue, if it was in fact an issue. But Eric assured me that's not the case, and that the hole will improve the problem, since he did that to his too. Of course, mine isn't put back together yet either. So I haven't had a chance to see what difference it makes. And my main issue (before) was 3rd gear, not 2nd. Although 2nd was stiff when cold.

But I'll let you know how it works for me when I have it functional again.

Thanks for chiming in! (as always!)

D.

 

If you look at all the rotating mass of any gear box configuration the syncros have a lot of work to do. The lower gears almost always have wider ratios that close up as the gears get higher. That means 1st has a harder job than 2nd and 3rd is a little easier still. Then there is the problem of many transaxle cars needing to lube the gear box and diff with the same oil and their lubrication requirements are often in conflict. The 308 vintage cars also have iron syncros which often do not work great unless hand lapped to start with. They take forever to seat well and work well on their own and if lousy oils are used they can get glazed and never work well.


All and all they are pretty tough gear boxes but about half or more that roll in here don't work worth a s##t because of a mixture of wrong oil, too old oil, badly adjusted linkage, bad shift bushings or glazed or otherwise beat up syncros. Everyone is looking for a magic bullet and it is just like a good engine tune up, turning one screw ain't going to fix it but if someone with the knowledge to do so takes the time they can shift very well. Our 2 cars, the TR and the 328 get a 20 second warm up and get into 2nd gear about 50 yards from the driveway without hesitation. The ones that won't do that are just not right.

 

My 308 with new syncros shifts like butter stone cold too. It works like a transmission should. Ferrari says to replace syncros every 30K, at least in the boxer WSM.

 

Interesting. In the original R&T 328 road test back in May 1986, they reported that second gear was unattainable after a cold California morning start in their brand new test car.

I always took that to mean it was a design issue.

 

In colder climates it certainly pays to let the gbox oil warm up. And, for whatever reason going from 1st to 3rd is a heck of a lot easier, and less prone to damaging syncros than 1st to 2nd on a cold morning right out of the driveway.

Like just about everything mechanical, show it some consideration and regular maintenance and you (and it) are going to be happier in the long haul.

 

I could not find a logical explanation hence why I started looking at physics, chemistry and fluid theory... So I want to stimulate a discussion to arrive at a conclusion and not be right to start with and impose my solution.

As to why we can come out of first: It is on a different gear unit with a bigger synchro (Ferrari is rare in that is has synchros on rev. and 1st). It also is engaged at a standstill, and the process of disengagement does not require help from the synchro.

As to why it is easier to get into 3rd when cold: I suspect that we shift slower when on a cold engine, this means there is a bigger drop in the RPM, which lands the layshaft and mainshaft RPM's closer to the 3rd hear ratio than the 2nd gear ratio, meaning the synchros have less to do... I'm sure if we tested a cold shift at 5000 RPM into 1st to 2nd, then from 1st to 3rd, it would work out to about the same.

Discuss...

 

My car never had a problem with second from day one. 3rd was difficult on a fast upshift and when I went through the gearbox I found 2nd gear syncro had been done and 3rd was worn out. I bought new syncros anyway and replaced them again and it simply slips into any gear with no warm up at all and thats in 10C weather too.

 

I cannot believe that Ferrari would recommend replacing Boxer synchros in 30K miles...WTF--I have another idea Ferrari, how about building a better gearbox!

As for mine, my gearbox only objects to second for about a minute or so. However, as a rule, I tend to skip second altogether whenever possible and try to match the first to third shift seamlessly. I have no interest in rebuilding a gearbox under my tenure.

 

Having a synchro on reverse wouls definately be rare. My 308 doesn't have a synchro reverse, and I strongly suspect yours does not as well.

But rare synchro on first? Have you owned a car newer than the 1965 model year? Everything has a synchronised first.

 

My understanding was that the 308 did not have a synchro on first either. Is this not correct? I have always made sure to come to a complete stop before engaging first for this reason.

Aaron

 

This has always been my theory. I have noticed that when cold if you rapidly throw second it will go in but you might get a slight clunk doing so. Also, If you wait too long on a slow shift (after giving up on second) third will balk. When this happens, I go to neutral, release the clutch pedal and blip the engine to about 3Krpm, then light pressure on second and it will always go in without complaint. It really does feel like the thick oil is putting the brakes on the shafts.

Dave

 

I think what he meant was that reverse shares a syncro slider with reverse. I dont believe he meant that its rare for a Ferrari to have syncro on 1st.

From 40 plus years of cars and gears and engines, and over 10 years heavy reading and tinkering with Ferrari's, it appears the gearbox was WAY overbuilt, and in many cases take many miles to bed in the syncros. Because many of the cars wernt driven much, 20 and 30 years later some of these cars still havnt bed in the syncros, or may in fact have glazed the cones as Brian eluded.

Does drilling oil bleeds on the shift rod guide holes eleviate pressure? Perhaps. But then again, is there really any reason to work the car that hard when its cold? Maybe its better to be held back until the cars ready to go?

Build a better gearbox? Well, I dunno, they have lasted over 30 years with very few failures, even under thousands of miles of hard track driving, and they can take up to 800 HP (various sources including Norwood) and not break. Name another manufacturer that can make either of those claims for a gearbox stuffed behind a 250 HP engine. I dont think you can find many. HD gearboxes arent always easy to shift, its a compromise we have to accept.

 

None of the 308/328 gear boxes had syncronized reverse but they were the last not to have it.

 

Because of the garbage gear oil they used. Ferrari has long been married to use of poor quality lubricant products because of the product endorsement money they recieve.

That is probably what inspired the 30k replacement Paul spoke of.

 

Mine had 2nd gear trouble when I got it, it worked harm okissh but not cold. I bought a new syncro to install while everything was apart for an engine rebuild, but when I inspected everything the origunal synco was perfect.

It turned out the issue was simply the the alignment of everything in the case and the shifter linkage. If everything isn't perfect the interlock on the 2nd gear shaft doesn't disengage the way it should and it's just flat impossible to get the trans into second gear. At least that was the problem with mine as there was no hint of a second gear issue when I put it back together. I'm sure cleaning the gick out and putting in good oil was part of it too though.

 

Very common problem, and often caused by the guy assembling the thing new in Maranello.

 

All I know is that the 328gts, Gallardo and F430 all had a hard second gear when a cold start and I live in hot and humid Florida. The Testarossa didn't have this peculiarity, also there's a Forza magazine that explains the hard second on 308 and 328.

 

Brian, what's the approximate cost range to take everything apart and make it right?
2nd is perfect when warm but absolutely will not engage when cold, regardless of the oil.