901 trannsmission and 1st gear, Did Porsche ever document issues? Options

[PRS914-6]

I'm sorry but when these discussion come up I shake my head. If Porsche didn't want you to shift into first while moving they wouldn't put a synchro on it.....c'mon guys you don't need to go to second, or any other gear first. If the components are fresh, the teeth sharp and sliders not worn it will slide right in without effort. (if built properly)

If you want to discuss the merits of reducing wear by shifting techniques (avoiding first) that is another discussion not valid here. This is simple mechanics.

The biggest problem is that people want to put in a new synchro and complain that it doesn't shift right but didn't change the shift sleeve and dog teeth. If you change the dog teeth, the synchro and the slider it will shift perfect with a proper clutch system and good bushings. I have stated this many times here, you can't judge a slider by the looks of the teeth. There is internal wear and ramp angles that can not be easily measured. If your 1st through 3rd sleeve is original then change it and look close at the 4/5

Although I have a 915, the design is the same and bulkier. I shift all day long to first at 30/40mph, it doesn't balk and I don't have to stick it in another gear first or pray before shifting. I use it. It shifts as good if not better than my Subaru did and my 901 was the same.

Anyone that has been in my car will vouch.... I don't baby the shifting when I want to play.

So to close my excessive rant....Although not a perfect tranny, if everything is correct, a 901 drives like most any car. If it doesn't something is WRONG. Period. It should not and does not need special shifting training, techniques or snake juice. End of rant. Thank you for reading (IMG:style_emoticons/default/biggrin.gif)

[ConeDodger]

Ya... I've been in his car. He doesn't baby it. She winces every time he opens the garage! (IMG:style_emoticons/default/evilgrin.gif)

[Bartlett 914]

I'm sorry but when these discussion come up I shake my head. If Porsche didn't want you to shift into first while moving they wouldn't put a synchro on it.....c'mon guys you don't need to go to second, or any other gear first. If the components are fresh, the teeth sharp and sliders not worn it will slide right in without effort. (if built properly)

If you want to discuss the merits of reducing wear by shifting techniques (avoiding first) that is another discussion not valid here. This is simple mechanics.

The biggest problem is that people want to put in a new synchro and complain that it doesn't shift right but didn't change the shift sleeve and dog teeth. If you change the dog teeth, the synchro and the slider it will shift perfect with a proper clutch system and good bushings. I have stated this many times here, you can't judge a slider by the looks of the teeth. There is internal wear and ramp angles that can not be easily measured. If your 1st through 3rd sleeve is original then change it and look close at the 4/5

Although I have a 915, the design is the same and bulkier. I shift all day long to first at 30/40mph, it doesn't balk and I don't have to stick it in another gear first or pray before shifting. I use it. It shifts as good if not better than my Subaru did and my 901 was the same.

Anyone that has been in my car will vouch.... I don't baby the shifting when I want to play.

So to close my excessive rant....Although not a perfect tranny, if everything is correct, a 901 drives like most any car. If it doesn't something is WRONG. Period. It should not and does not need special shifting training, techniques or snake juice. End of rant. Thank you for reading (IMG:style_emoticons/default/biggrin.gif)

(IMG:style_emoticons/default/agree.gif)

It is reverse you are not to shift into when rolling. That gear is not synchronized.

[pcar916]

1st gear is not synchronized on the downshift. That's why I added blocks to synchronize mine in both directions. Even then I don't downshift into it unless I'm at the barest minimum of speed. Then I can take it out of gear just fine and it has no problems. Still, a habit from earlier times...

When I'm at a stop, I'll nudge it slightly into 2nd gear until I feel a little resistance, then shift into 1st. There is no need to shift all the way into 2nd. Now, there are two obvious questions, 2nd gear synchro wear and 1st gear dog tooth wear ($!).

1. Over the years I halfway expected that 2nd gear nudge to take a toll on my 2nd gear synchro, but that hasn't happened in 19 years. So I figure it's a non-issue.

2. I'm still using the same 1st gear the car came with and the dog-teeth are just fine... in fact, that's the same synchro. This is the street transaxle we're talking about, but it's been tracked (DE's, and several years of AX'ing) a lot as well. The other two don't see much use.

[Bartlett 914]

1st gear is not synchronized on the downshift. That's why I added blocks to synchronize mine in both directions. Even then I don't downshift into it unless I'm at the barest minimum of speed. Then I can take it out of gear just fine and it has no problems. Still, a habit from earlier times...

Are you saying first is only synchronized when up shifting? How does one up shift into first?

[PRS914-6]

1st gear is not synchronized on the downshift. That's why I added blocks to synchronize mine in both directions. Even then I don't downshift into it unless I'm at the barest minimum of speed. Then I can take it out of gear just fine and it has no problems. Still, a habit from earlier times...

When I'm at a stop, I'll nudge it slightly into 2nd gear until I feel a little resistance, then shift into 1st. There is no need to shift all the way into 2nd. Now, there are two obvious questions, 2nd gear synchro wear and 1st gear dog tooth wear ($!).

1. Over the years I halfway expected that 2nd gear nudge to take a toll on my 2nd gear synchro, but that hasn't happened in 19 years. So I figure it's a non-issue.

2. I'm still using the same 1st gear the car came with and the dog-teeth are just fine... in fact, that's the same synchro. This is the street transaxle we're talking about, but it's been tracked (DE's, and several years of AX'ing) a lot as well. The other two don't see much use.

I don't understand the synchronizing statement either. They don't grind if properly setup on a downshift. Period. One thing that throws a flag up though is " I'll nudge it slightly into 2nd gear until I feel a little resistance" This indicates gear spinning to me and a possible clutch drag. When there is no gear spinning the synchro and bands "relax" and the shift sleeve can slide over them very easily(unless the dog teeth are dull and the shift sleeve is worn and dull too) Yes, once in awhile the teeth hit straight on and requires another try but rare if stuff is not worn. Porsche clearly recognized first gear issues as noted by their changing and updating the inner teeth system so yes, there was some subtle improvements especially to the 915 for first gear.

To be fair about all this, I have a special clutch disk with a marcel spring only on one side. It disengages quickly and easily without need to slide on the input shaft. The cost is a little more wear on the outboard side of the disk but helps fast shifting. Also have a hydraulic clutch so no cable issues. I luckily have no issues as mentioned anywhere in this thread so I know these trannies can be setup to run good (not perfect)

[dlestep]

There is a reason why reverse and first are locked out of the "racing H" pattern.
1st is for take-off only, after that, it's used to get into the garage.
~
All state side write-ups of the day were about how WIERD the shift pattern
was. "It's wierd, not like our stick shifts."
Because, in America, 5th gear started out as an overdrive.
Hell, GM was still producing some cars with 3 speed stick shifts, in 66 and 67.
Yes, others had 4 speeds.
I think someone at GM, at that time, thought that if its' car had 5 speeds,
it would go off the end of the earth.
In 1967, if I remember correctly, the 911R used a second 5th in 4th position, and
it proved to be a good move, because they lost the original 5th gear during the
endurance attempt that originally was started by the 906. When it failed, they
simply shifted to 4th position and kept going, sustaining 130mph.
~
I love my "racing H" pattern.

[Dr Evil]

Wow, plenty of anecdotal evidence here. I have confirmed with several factory trained technicians from the old school that it was advertized and supposed to be recommended that you are not to down shift into first for the purposes of stopping/slowing. I dont care what people think they know based on design, blah, blah. Armchair engineering does not replace the fact that the intention and design, as taught to the factory techs, was not to use first as I have stated. Is it possible? Yes. Should you, no. Does problems getting into first tend to indicate need for parts replacement, yes. Will a well built and maintained trans take 1st abuse? Sure. This should not be used as proof that you should do so.

The OP asked about getting into 1st while coming to a stop. That is what I addressed.

Consequently, visual inspection of a slider is plenty adequate and ramp angles do not need to be measured. I have proven this time and again in rebuilds and in my selection of good used parts for such. Practice v supposition.

[Dr Evil]

Oh, I dont get that synchro statement either. You can not upshift into 1st so adding more bands and blocks means nothing unless done so you can use a 2-5 set of teeth. Why would someone do this intentionally other than for the aforementioned?

(IMG:style_emoticons/default/confused24.gif)

[SirAndy]

You can not upshift into 1st

Sure you can!

I start the car in neutral and upshift into 1st and then go from there ...
(IMG:style_emoticons/default/biggrin.gif)

[Dr Evil]

You can not upshift into 1st

Sure you can!

I start the car in neutral and upshift into 1st and then go from there ...
(IMG:style_emoticons/default/biggrin.gif)

(IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/tongue.gif)

[PRS914-6]

Wow, plenty of anecdotal evidence here. I have confirmed with several factory trained technicians from the old school that it was advertized and supposed to be recommended that you are not to down shift into first for the purposes of stopping/slowing. I dont care what people think they know based on design, blah, blah. Armchair engineering does not replace the fact that the intention and design, as taught to the factory techs, was not to use first as I have stated. Is it possible? Yes. Should you, no. Does problems getting into first tend to indicate need for parts replacement, yes. Will a well built and maintained trans take 1st abuse? Sure. This should not be used as proof that you should do so.

The OP asked about getting into 1st while coming to a stop. That is what I addressed.

Consequently, visual inspection of a slider is plenty adequate and ramp angles do not need to be measured. I have proven this time and again in rebuilds and in my selection of good used parts for such. Practice v supposition.

Anecdotal? I'm sorry doc but although I respect you, in my opinion you bring most of this fairytale stuff based on your own opinion and never able to produce a service bulletin, official instructions from Porsche or anything from Porsche accept "hear say" or "your say". You did this on the pinion bearing installation and never produced a single document. I had to post the service manual. You assume I have no experience with transmissions. You should not make such assumptions. My opinion is based on my success from many years of building, not on speculation.

Porsche used this synchro system all the way to the G50. What is that about 20 years of usage? If people couldn't downshift into first, NOBODY would buy a Porsche, the lemon law would be in full swing, there would be recalls and Porsche would never sell another car. Not to be rude, and I apologize, but please, get real.

If you want to tell people this stuff, use old shift sleeves by "looking", tell people not to shift into first, that's OK it's free speech but when you preach it as Porsche law and I adamantly and totally disagree I feel I owe it the group to hear the other side and they can do as they like. The best advice is to have a clutch that works properly. You can avoid wear in any gear if you don't use it.

The OP asked for official documentation and you said "It is a known fact that 1st is not supposed to be down shifted into while rolling. "

Please provide the documentation for your statement of "known fact" that was asked for and not rumor or your opinion. I would like to see the documentation too.

Did you ever think that most of the wear is because you use first in traffic the most and in and out of neutral constantly? Of course it wears the most! It doesn't mean there is a design flaw or you shouldn't use it. The synchro system works the same in first as it does in the rest of the gears. Because first is worn out in 20 years is perfectly logical.

As I said, this is not a conversation of "how" you should shift to limit wear but the mechanical capabilities of the design and should it grind going into first or not. It shouldn't! I'm sure I would agree with you on the topic of shifting techniques to reduce transmission wear. That's pretty simple.

[Jon B]

You can not upshift into 1st

Sure you can!
I start the car in neutral and upshift into 1st and then go from there ... (IMG:style_emoticons/default/biggrin.gif)

Yes, with car at standstill, from neutral into 1st gear is an upshift.
1st gear synchromesh is designed for both upshift and downshift.

From neutral into 1st, with car at standstill...



From 2nd into 1st, with car in motion...



Jon B.
Vista, CA

[Eric_Shea]

That kinda settles that.

Now... try a standard "Dino Juice" lube and see if that makes a difference. I experienced similar issues the OP did with Liquid Moly 75/90. I think some of the newer synthetics are a tad too slippery to allow the syncros to speed up as described above.

Try shifting immediately into first from second as you come to a light. If it goes into gear under those circumstances (the gears don't have time to slow down), you may want to try a standard straight 90w dino lube.

Also... mine was all new inside. It's gotten better with age.

[bulitt]

There is a reason why reverse and first are locked out of the "racing H" pattern.
1st is for take-off only, after that, it's used to get into the garage.
~
All state side write-ups of the day were about how WIERD the shift pattern
was. "It's wierd, not like our stick shifts."
Because, in America, 5th gear started out as an overdrive.
Hell, GM was still producing some cars with 3 speed stick shifts, in 66 and 67.
Yes, others had 4 speeds.
I think someone at GM, at that time, thought that if its' car had 5 speeds,
it would go off the end of the earth.
In 1967, if I remember correctly, the 911R used a second 5th in 4th position, and
it proved to be a good move, because they lost the original 5th gear during the
endurance attempt that originally was started by the 906. When it failed, they
simply shifted to 4th position and kept going, sustaining 130mph.
~
I love my "racing H" pattern.

(IMG:style_emoticons/default/agree.gif) My 08 vette had 6 speeds. After a while you are thinking WTF gear am I in? IMHO sometimes more aint better. Cruising along and want to pass on a double lane road, try shifting quickly from 6 to 3rd or to 2nd. good luck.

[Dr Evil]

[quote name='PRS914-6' date='Nov 15 2013, 03:32 PM' post='1957298']
Anecdotal? I'm sorry doc but although I respect you, in my opinion you bring most of this fairytale stuff based on your own opinion and never able to produce a service bulletin, official instructions from Porsche or anything from Porsche accept "hear say" or "your say".

Well, it is true that I poll those that have been doing this for 40+ years, some are even on here, I do not have a service bulletin for everything and when I get credible info from a credible source, or several credible sources, I try to pass is on so that the community as a whole can benefit. You can not show where my info would or has caused harm. No, I do not have service bulletins for everything. Not only that, I have found the following the book exclusively leaves gaps in ones growth, knowledge, and does not allow for better techniques to be developed and used. I could care less if anyone believes me, I make no money on my advice and offer it for free in order to help. If you want to call it my opinion, or hear say, which kind of sounds like you feel I am making shit up, then that is your prerogative. I dont like it, but it is a free site.

You assume I have no experience with transmissions. You should not make such assumptions. My opinion is based on my success from many years of building, not on speculation.

I make no assumption. I state my experience, much like you do. My experience past what the bulletins state. My experience in over 300 successful rebuilds. What I am stating is not speculation, either. If you feel slighted, I am sorry for that. My intention is to be a help around here. If I see something that I have known to be incorrect in my experience, or in the experience on those that I have learned from that have many years and training, I will state what I know. Acting as if it is heresy without a cited bulletin discounts my experience and the experience of those that have come before me. My work and long line of satisfied and repeat customers speak for themselves.

Porsche used this synchro system all the way to the G50. What is that about 20 years of usage? If people couldn't downshift into first, NOBODY would buy a Porsche[] Not to be rude, and I apologize, but please, get real.

I never said that you COULD NOT down shift into first. Not only that, the 901 is the most anemic of the design. Beefing up, as you alluded to in the 915 (and more forward), negates a lot of this wear. Just because mechanisms are similar in these boxes does not mean they are the same. Telling me to "get real" is rude and not conducive to discourse of discovery. You disagree, that is fine. You have that right. I disagree with you, and for similar reasons such as experience.

If you want to tell people this stuff, use old shift sleeves by "looking", tell people not to shift into first, that's OK it's free speech but when you preach it as Porsche law and I adamantly and totally disagree I feel I owe it the group to hear the other side and they can do as they like.

I cite where my info comes from. If people choose to follow it and trust me because of the help I offer around here, and have done for many years, and the services I provide, then that is understandable. Telling your side is great. Being respectful is a nice thing as well. I am getting sick of all of the A-holish behavior that has been popping up lately when people disagree. I am reflecting this behavior at times and it is not me and I am saddened by this fact. Thus, I disagree with you as I am stating, and respect your experience as it is. Are you preaching Porsche law? Is there no better way than the 40 yr old manual?

The OP asked for official documentation and you said "It is a known fact that 1st is not supposed to be down shifted into while rolling. "

Indeed, I misspoke that it is a "known fact" as you dont know it and I ahve no bulletin so it must only be known by the people I have consulted and myself.

Please provide the documentation for your statement of "known fact" that was asked for and not rumor or your opinion. I would like to see the documentation too.

As stated above. Calling my statement rumor is rude and attempts to devalue a point of view, information and experiences you do not share. That does not mean it is wrong.

Did you ever think that most of the wear is because you use first in traffic the most and in and out of neutral constantly? Of course it wears the most! It doesn't mean there is a design flaw or you shouldn't use it. The synchro system works the same in first as it does in the rest of the gears. Because first is worn out in 20 years is perfectly logical.

In first the ratio is the greatest. This is why the wear is grater than on 5th which is closer to 1:1 ration and low impact on shifting. I am sure you know this, but you asked. First will be abused the most, yes, but you can mitigate this significantly by shifting the way I was told we are supposed to. You argue the validity of that claim, but then you agree with the application of the strategy. Stop and go traffic is hard not to go in and out of first a lot, and it is in slower speeds that this is done so is not my objection. My point is using 1st as a slow down gear.

As I said, this is not a conversation of "how" you should shift to limit wear but the mechanical capabilities of the design and should it grind going into first or not. It shouldn't!

Sure, I dont dispute this

I'm sure I would agree with you on the topic of shifting techniques to reduce transmission wear. That's pretty simple.

Addressed previously


Saying you should do something because of the capabilities of the mechanism is like saying that you can drive around in 1st gear at 50+mph all day long. You can, but you should not.

I am sorry if I seem argumentative. My intention is to discuss, educate, garner things from others, and share. Arguing really yields not of this.

[eimc]

I have been a porsche mechanic since 1968 working for Porsche and Porsche dealers. In 1970 working for Porsche owned shop I was the unit repair person for years. I repaired 914 trany 1st gear problems a couple times a week. All the Porsche zone reps would do R&D at our shop. We were given stickers that went in the owners manuals or on the dash that said complete stop before 1st gear engagement. I still work on some of these 914's today(not many)and none have the stickers on the dash but I always look in the owners manuals (to see if I did the pre delivery inspection) and they are still there. That' all this old fart can tell you Take it or leave it

[Dr Evil]

Thanks for chiming in, Paul. Paul is one of my experts that I cite, and an all around great guy.

[PRS914-6]

Doc, no disrespect intended at all. I would simply suggest in future posts to state "It's my opinion" or "in my experience" rather than "It's a well known fact" or "Porsche changed that" and similar statements that can't be verified except by rumor and are controversial.

I call you on these issues simply because you infer, perhaps unintentionally that there is a hard and fast rule established by Porsche or the Porsche community that I feel is not accurate and although your info is generous, free and appreciated by all, it can be misleading when stated as a fact instead of an opinion.. I wouldn't ask for documentation if it was your opinion. Hope that explains it....

My apologies if that rubs you wrong.

[Dr Evil]

Then, shall I expect documentation or similar when you make a statement?

I have posted in various placed in my 19596 posts here where I get my info when asked about it. I do not find if fluid, or realistic to have to post disclaimers prior to each post of advice. Such would be cumbersome and ridiculous. Based on my presence here, and my known experience, I have earned the right to state things and not necessarily need to justify them with IMHO or a citation. It is realistic to respond to inquiries with honest answers, but to require disclaimer before every post is to put the assumption forward that if such is not done then everything is heresy.

I do not feel that I will change your mind on this, nor should you expect to change mine for the reasons aforementioned. I do, however, appreciate the fact that you have stated it, everyone can read it and draw their own conclusions, and we are respectfully sharing and disagreeing.