More and more I am noticing that it is very difficult to get into 2nd gear on my '98 coupe. It is especially bad with the colder weather. Often it takes an excessive amount of force to pull the shifter into 2nd gear, but other times I get a sensation of the shifter being pushed back out a couple of times before going into gear.

It is this second feeling that concerns me the most. I can only describe it as a feeling of gears not meshing properly, but there is no grinding sound coming from the car. The transmission had been rebuilt (14,000 miles ago), and the syncros were all replaced where any wear was noticed.

For comparison I took my '01 Z06 out yesterday (only 5,000 miles on this car), and I had the same difficulty getting into 2nd gear and the occasional pushing back out of gear until the transmission warmed up.

Any ideas or explanations for me?

LO PHAT

 

I have always found 2nd gear in Vettes to be a bit notchy depending on shifter. You might try a shifter alignment first.

 

Try a fluid change 1st.

 

Thank you for your reply. You are quite correct. I should have mentioned this in my post, so let me add here that I have already done a shifter alignment using the method described in these forums. I also maintain my car's clutch using Ranger's technique for changing the fluid.

LO PHAT

 

Change the oil in the trans. Stick shift cars are better than they used to be in the cold but not PERFECT. My 69' Vette was almost impossible to shift the first mile or so when it got cold out (I rarely had it out except for the occasional winter "stretch"). Since they got away for 90W gear lube, they are easier to shift in the cold. Many people have had good luck with fresh lube in the trans to stop the notchy shifting.

 

You know my older 4 speed Vettes shift more smoothly than my 02 with only 10,000 miles on it. My 02 is very notchy going into second and 3rd and 5th when it's cold. Fine once it's warmed up. I think it's the nature of the beast. My 98 and my 05 were the same. A fluid change might help.

 

In my experience, many cars with performance transmissions have a problem with 2nd gear when the transmission is cold. And the problem gets worse when the weather is cold, as the fluid is thicker. Once the transmission fully warms up and the fluid thins out, it gets easier to shift into second.

I have found two solutions to this problem -- Red Line synthetic ATF, and Mobil 1 synthetic ATF. I've heard from others that Royal Purple and AMSOIL ATFs are also good at solving this problem. My favorite is Red Line. Their fluids are excellent. I run their 75W90 in the differential. Right now I have Mobil 1 ATF in the tranny on my '04 Z06, but in the spring I'll be changing it over to Red Line. I have used Red Line fluids in other balky transmissions and it has solved the problem each and every time, and improved overall shifting and performance of the transmissions I've used it in.

Give it a try. It's a cheap fix, if it works. Certainly a lot better than dealing with a tranny rebuild.

 

Of note, your 98 has paper blocker rings and not all synthetic basestocks are compatible with these blocker rings. There is a good discussion of this issue in the sticky thread "Weights, Measurements..." at the top of the C5 General section way down on the 1st page of that thread under the section in the thread titled "Tough Shifting".

The AMSOIL fluids seem to work well with these blocker rings. Though you might have a mechanical issue, I'd also recommend a cheap fluid change before spending $$$ on a tranny repair. My recommendation is the AMSOIL Torque-Drive Synthetic Transmission Fluid (product code ATD1G - you'll need one gallon). This is a Dexron III fluid that is very very shear resistant as it has no viscosity improvers.

 

Thank you for your replies. A transmission fluid change is on my list of things to do (hopefully tomorrow since I'll have the day off for New Years). I am skeptical, however, that it will make much difference since the fluid presently in the transmission is relatively new.

Subdriver: You bring up a great point about the paper blocker rings. I have researched and read all of the threads in these forums on this issue, and I even posted in many of them myself. It seems there are two camps around here. There are those that swear Royal Purple Synchromax is "the fix all" for any transmission, and then there are those who won't use anything other than AMSOIL. I already have the Royal Purple oil ready to go, but I have read many posts about possible negative effects with the paper blocker rings. Most posts and Royal Purple's website, however, indicate that it is compatible.

I'm keeping my fingers crossed,
LO PHAT

 

I was on the fence when it came to RP and paper blocking rings. I read threads on several forums and never got to the true facts about paper blockers. More of a myth it seems. What sold me on trying the RP was their website claiming it was compatible. Been 10,000 or so miles and nothing wrong yet. It did make a nice change in shifting.

 

While I agree that it is hard to find true facts, particularly given the lack of disclosure on many oil companies websites (for example, try to determine what basestock Mobil 1 or Royal Purple use), I don't agree that it is a myth.

In my opinion, the issue related to paper blocker rings is the same issue related to seals (though we don't hear much about the seal issue in the C5 section because these cars came with synthetic from the factory).

The differences in how one synthetic will impact things like seals and paper blocker rings vs how another will impact them goes back to what is "synthetic".

All synthetics are not equal. The API has not come out and defined what is "synthetic", but rather, classified oils into five major groups.

Group I base oils are the least refined of all of the groups. They are usually a mix of different hydrocarbon chains with little or no uniformity. While some automotive oils use these stocks, they are generally used in less demanding applications.

Group II base oils are common in mineral based motor oils. They have fair to good performance in the areas of volatility, oxidation stability, wear prevention and flash/fire points. They have only fair performance in areas such as pour point and cold crank viscosity. Group II base stocks are what the majority of engine oils are made from. 3000 mile oil changes are the norm.

Group III base oils are subjected to the highest level of refining of all the mineral oil stocks. Although not chemically engineered, they offer improved performance in a wide range of areas as well as good molecular uniformity and stability. By definition they are considered a synthesized material and can be used in the production of synthetic and semi-synthetic lubricants. Group III is used in the vast majority of full synthetics or synthetic blends. They are superior to group I and II oils but still have limitations. Some formulations are designed for extended oil changes. AMSOIL XL Motor Oils, Castrol Syntec and many others fall into this category.

Group IV are polyalphaolefins (PAO) which are a chemically engineered synthesized basestocks. PAOs offer excellent stability, molecular uniformity and performance over a wide range of lubricating properties. AMSOIL SAE Synthetic Motor Oils and Mobil 1 primarily use group IV basestocks (though recent info posted on the oil forum indicates that Mobil 1 is also now using a significant proportion of Group III basestock). PAO is a much more expensive basestock than the highly refined petroleum oil basestock of Group III.

Group V base oils are also chemically engineered stocks that do not fall into any of the categories previously mentioned. Typical examples of group V stocks are Esters, polyglycols and silicone. Red Line uses an ester basestock.

In the 90s, Mobil filed suit against Castrol for falsely advertising Syntec oil as synthetic, when in fact it contained a Group III, highly hydroprocessed mineral (Dino) oil, instead of a chemically synthesized (group IV or V) basestock. Due to the amount that the mineral oil had been chemically changed, the judge decided in Castrol's favor. As a result, any oil containing this highly hydroprocessed mineral (Dino) oil (currently called Group III basestock by the American Petroleum Institute) can be marketed as a synthetic oil. Since the original synthetic basestock (polyalphaolefin or PAO) is much more expensive than the Group III basestock, most of the oil blenders switched to the Group III basestock, which significantly increased their profit margins.

Today, most oil companies use a Group III synthetic in their basestock. Mobil 1 probably uses a blend that is heavy on Group IV with some proportion of Group III and V blended in. AMSOIL does make a Group III, but the majority of their fluids, and their tranny fluids, use a Group IV basestock with some undisclosed portion of Group V ester basestock blended in. Others such as Red Line use a Group V polyol ester basestock. Given the wide variance in basestocks, it isn't unreasonable to believe that one will behave differently with respect to porous material than another.

Group III basestock will probably have no different impact on paper blocker rings than will a typical Group II mineral oil as the basestock is really just mineral oil, albeit a very highly refined and clean (read less parafins) mineral oil. Group IV PAO basestock is well known for shrinking porous material - doesn't sound good for things like paper blocker rings and seals. Group V ester basestock on the other hand, is well known for swelling porous materials like paper blocker rings and seals - again, doesn't sound good for paper blocker rings and seals.

So how do the makers of Group IV basestock synthetics like Mobil 1 and AMSOIL deal with this issue? They learned a long time ago that by adding a small percentage of Group V ester to a predominantly Group IV PAO basestock the fluid's impact on porous material could be significantly altered. The result in general, is that AMSOIL Group IV synthetic basestock will actually very slightly swell the porous material, e.g. rejuvinate what may be dried out seals. They also long ago discovered that by adding a small percentage of Group V basestock to Group IV basestock, the fluid's coefficient of friction is dramatically reduced which leads to less fluid friction, less heat and improved efficiency.

While I acknowledge that this issue is probably extremely well understood by the engineers at Royal Purple, what I found frustrating when I chose to switch from Mobil 1 years ago is that this info is not well disclosed on Royal Purples website. I actually emailed them and asked what they used as a basestock and they were very non-commital. I suspect, but don't know and they aren't saying, that they use a basestock that is a blend of Group III, IV and V. How that impacts porous materials, I can't say.

For those with paper blocker rings, I hope they last. My gut feeling is that, whatever fluid you chose, their day's are numbered.

 

I spent the morning changing the transmission fluid on my Corvette. I would love report that it went smoothly, but it didn't. Despite having the car level, the fluid warm, and allowing more than adequate time for all of the fluid to drain, I was only able to get three quarts of Royal Purple Synchromax back into the transmission. This indicates to me that an entire quart of the old fluid never made it out or the transmission.

I took the car for a drive after the fluid change. I had read in other threads that a positive difference is usually noticed within the first 50 miles. Even though I've only put about 25 miles on the new fluid as of this post, I’m already worried because I feel no difference at all in the way the car shifts.

More to come....

LO PHAT

 

Wow! That is a lot to digest (even after reading it twice). Thank you so much for the detailed information!

LO PHAT

 

My pleasure and hope your tranny fluid change works out. I wouldn't worry too much about only getting 3 quarts back in. While that's a little low, I've done a few changes that I only got about 3.25 quarts back in. If your car was level and you filled it until fluid came out the fill hole, its filled to the proper level.

 

This year I replaced my trans fluid with Amsoil ATD. I only got about 3 1/4 quarts back in also. That was consistent with last year's change. The car is a '98 M6 with 40K miles.

After about 500 miles I have really seen a difference. The cold shifting performance improved immediately and the entire shift action is becoming smoother and more consistent no matter how hot or cold the trans. The improvement was small at first but after a month of driving it just keeps getting better. Well worth the money and time.

 

Thanks for the info!

 

We had and interesting discussion awhile back here about the ATF vs the "syncromax" fluids. GM, and most of the high-end lubricant companies offer both types. However, only Royal Purple recommends the syncromesh oil for the Vette tranny. The others, including of course GM, recommend the ATF. I tried the GM syncromesh, based on some positive reports here, and it was unaccepteble, giving the same
shifting characteristics you report.
I switched to a cheap Pennzoil Dexron III (not the newer dexron VI) and the shift improvement was immediate.
Later, I pulled and cleaned/lubricated/adjusted my shifter.
Now my 2000 shifts as well as I ever remember, and actually almost seems to shift a little crisper when cold.

Just my experience. (Your mileage may vary).

DG

 

I'll throw my two cents worth in here regarding the paper blockers in the BW transmissions. I had one in my '99 that it wasn't supposed to get for that year. I used Mobil 1 in it and ended up trashing the trans. I gave up and put a Tremec into it. No more problems.

 

Update ... More help is needed.

The car now has nearly 200 miles on it since I changed the transmission fluid. I'm not at all happy with what I've noticed. 1st, 5th, and 6th gears are silk smooth to shift into (actually improved from before). 2nd, 3rd, and 4th gears are now not always possible to shift into. 2nd gear without a doubt seems worse (or at the very least no better), and 4th gear being difficult is something I hadn't previously noticed. I never hear or feel any grinding going into the gears, but the shifts are well beyond what most would call notchy. I feel like I'm having to force the car into gear.

For those just joining: The transmission was completely rebuilt about 14,000 miles ago (new gears, synchros, bearings, etc), and the clutch was also replaced at that time (pressure plate, disc, throwout bearing, flywheel). All of this was done to the tune of about $6,000 billed against the previous owner's extended warranty. I religiously maintain the car's clutch fluid with Ranger's method, and prior to this winter I had never experienced the "sticking clutch" problem. So far that has now happened three times (not from heat or hard driving) despite perfectly clean fluid. My shifter does have quite a bit of slop in it, and I did do the alignment procedure with no noticeable improvement.

Before I start listing a bunch of my worst-case scenario fears, I'd like to hear some recommendations or ideas from the rest of you. What might the issue(s) be? What repairs, adjustments, or tests can I perform at home to help narrow down the problem?

Thanks,
LO PHAT