Unauthorized Gear Change?

dkrace67

New Member
Messages
18
Likes
0
Location
MN
#1
I have had an unusual "problem/occurance" with my '98 323is where intermittantly it will kick itself out of gear. This occurs very randomly and only happens in first gear. Most likely scenario will be I pull up to a stop, put the car in neutral for some period of time, then put it in first and start to let the clutch out. As I'm doing that the gear shifter will violently pop out of gear and make a loud (soil your pants loud) clunk and I'll be in neutral. Again, it is intermittant and in order to avoid it (with some repeatability) I will cycle the tranny in and out of first several times before attempting to let the clutch out. This seems to avoid help and I haven't had it happen if I cycle it in and out of gear. Any ideas as to what is happening? Do I need to adjust the clutch? Is it time to replace the clutch (110,000miles)? Help! I'm running out of underwear!
 
Messages
4,412
Likes
5
Location
Wayzata, MN
#5
ahha, i found it. the ZF S5D 250G gear box can be known to pop out of 1st/2nd under load due to a faulty guide sleeve on first and second gear.

the guideshaft can be replaced, but you have to disassemble the gearbox.

if you bring it in, most dealers will want to replace them flat out.
 

grc

Member
Messages
258
Likes
0
Location
chicago burbs
#9
my trans was replaced under warranty, the rest of the car too, but that's another subject. there was NO WAY anybody was going to hold that shifter in position and keep it from popping out of gear(1st). not hot dogging at all, just a regular "as if you had a cop behind you" from a light start off and BANG! the first couple of times i thought i got plowed into it was so violent. i had to regain compsure and look around to figure out WTF happened. it started out doing it once in a while and very quickly became just about every time. nothing wrong with the clutch. still the original in the car, and the brakes too which is pretty amazing for 85k+. my bud owns a trans shop and tells me occasionally that he will not open up my trans, not that he doesn't know what he's doing, maybe he's been bitten by one?
 
Messages
4,412
Likes
5
Location
Wayzata, MN
#10
mjbst111 said:
how is keeping pressure on the knob bad
f's your synchro mesh up. never rest your hand on the lever. its not like a do or die thing, but its a wear and tear thing.

think that when you push the lever into gear, then let go once its in, it sits in a certain spot, even though you can kind of move it around. it sits in that spot for a reason.
 
Messages
880
Likes
0
Location
Pittsburgh, PA
#11
your synro's 'disconnect' once it goes into gear. try this: shift halfway into a gear, pull the shifter back out a little bit and try to put it into gear again. you'll grind like hell because the syncros are not syncronizing anymore and the speeds no longer match to put it in gear.

actually don't try that cause you'll grind your gears.

there is constant pressure on your shifter in every single gear you put it in. you can put pressure on it. you know your shifter is spring loaded. thats why it goes back to the middle. so when you put it in a gear isn't that spring pulling on it? does that mean its bad to use your shifter because of the pressure that it puts on the gear when it is engaged?
 
Messages
3,420
Likes
0
Location
Metuchen NJ
#13
found it

Why can't I rest my hand on the shift knob?

Ever wonder why people say that its bad to rest you hand on the shift knob while driving? Well, there is a reason, and good thing you listened!

Within the transmission itself, BMW has a specification of 0.004"-0.006" gap between each gear and the shifter rail in the transmission (for reference, a human hair is approximately 0.0035"). This gap allows for the transmission lubricant to acts as a barrier so that the shifter rail and gear are not directly touching, causing premature wearing of the gear (not syncros), shifter rail, or both.

When you make a 0.001" change at the shift knob and maintain pressure (like resting your hand on the shift knob while driving), the required 0.004"-0.006" gap is closed, preventing the lubricant to ride between the gear and shifter rail. Premature wear of the gear or shifter rail may hamper transmission shifting performance, gear engagement, or worse, require rebuilding or replacement of the transmission.

A recent popular fix for short shifter notchiness is the use of an excessively heavy, metallic shift knob. At only 3 oz. (approximately 100 grams), the factory shift knob is relatively light, in comparison with the available aftermarket knobs. We have analyzed the additional mass of the Rogue Engineering shift knobs (approximately 6 oz.) and have found that they're additional mass was not enough to close the 0.004"-0.006" gap. However, as we began adding more weight to the shift knob area, we did find that when the mass increased to 8 oz., the gap began to close. Using anything heavier than this would be the equivalent of driving with your hand resting on the shift knob. When considering an aftermarket shift knob, consider how much mass it threatens to add. Too much is a BAD thing for your transmission!

A more elegant solution to addressing the effort is the Rogue Engineering Weighted Selector Rod. While stationary, its additional mass does not change the internal dimensions of the 0.004"-0.006" gap, since it's below the leverage point of the shifter. Its additional mass aids in improving the shifter feel without the potentially negative drawbacks of weighted moments on other parts of the shifter mechanism.

Thanks to Jim Blanton for providing the specifications for this tech tip.
http://www.rogueengineering.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=RE&Category_Code=SNNN
 
Messages
880
Likes
0
Location
Pittsburgh, PA
#14
wow that is some pretty extensive BS.

So buy our shift knobs, they are precision made weighed and tested to not hurt your gears!
If that was true how long do you really think it would take to damage something. It would take forever and you would have to be pushing darn hard! And how long are you in 1st and 2nd gear. not long enough to damage. Take apart a transmission (or watch someone) sometime and then tell me pushing the knob is damaging. My cousing repaired saab manual trannies for a long time and i have watched. This damage is not possible. In fact the way they explain it is rediculas. "This 0.004"-0.006" gap allows for the transmission lubricant to acts as a barrier so that the shifter rail and gear are not directly touching, causing premature wearing of the gear (not syncros), shifter rail, or both." And pushing on this shifter will close this gap. well hell i better not breath in my car. Anyway its just BS

Besides, think about this guys problem before we change the subject. if a gear is trying to pop out, then obviously the shifter is not doing its job to keep it in gear. thats is why you would need to help it stay in. A jetta i used to have would pop out of fifth. I found that if i pushed it into 5 harder when putting it in gear. it would stay in.

dkrace67, try pushing it in gear harder and see if it stays in.
 
Messages
3,420
Likes
0
Location
Metuchen NJ
#15
ya i hear what u're saying mjb, but a bmw tranny and a saab tranny are different right?
i mean sure its a load of BS they way they setup thier product, but i've heard from many
people not to rest your hand on the knob...

so dkrace, shove it into 1st gear with a little oomf and let us know what happens
 
Messages
880
Likes
0
Location
Pittsburgh, PA
#17
i understand all trannies are different but they are all the same basic idea. I just have no idea how these things they say could 'rub.' You are very right i didn't take apart a bmw tranny yet but in seeing the idea behind the inside of a tranny, this article is hard to believe. They just throw out random big works to make it sound good.

I'll have to get more facts as well though.

i hear ya frolf, i just wanted to clear it up.

i rest my hand on my shifter from time to time because i'm lazy, and i have a heavier shifter knob because my other one broke off slamming it into second so i bought the cheapest one i could find. maybe i'll find out the hard way about the weight thing but i'm not worried. You can't worry about that stuff. Its a bmw.

Only other thing i would suggest if pushing it in harder doesn't help would be putting in new fluid, redline MTL. I have no idea if it would help or not but i'd try it. that stuff is great.

still have that audi bahn? sig says you drive a 535, i thought you had an audi maybe on top of your 535?
 

grc

Member
Messages
258
Likes
0
Location
chicago burbs
#18
ever see a punk in a mustang wangin the shifter back and forth at a light? they do wear out, and pretty fast too. all trans' are slightly different, but they are also very similar. some have nylon covering the shift forks, some are just metal. they all wear. check out the feel of different shifters and you will find some that have been in "mustang mode"- loose as a $2 hooker.
 
Messages
1,247
Likes
0
Location
NY
#19
I remember a long time ago my dad told me that he had a similar issues with his car, at that time it was one of these things, at least I think so.


Now, that is nowhere near an e36 but manual trannys are similar so maybe this will help somehow. He said that it slipped out of 4th (last gear) almost everytime and right after he put it into 4th. The reason for it was, a friend told him that you don't need to use the clutch while shifting into 4th, he said that it's useless and that even race car drivers don't use the clutch while shifting into fourth. Well, my dad listened and abused the tranny, after that it started acting up and he lost use of the 4th gear. He also explained what mechanically happened to make this occur but I don't remember. I'll try to ask my dad tomorrow if any of you are interested. Sorry for all the BS, just have nothing to do.
 
Last edited:
Messages
5,379
Likes
0
Location
Paderborn, Germany
#20
the knob story i heard plenty of times as well and i can imagine that there is truth within, for all trannies. example: the tranny in my mom´s opel astra. it is 5 speed manual. when in 3rd or 5th gear for example you can push the knob forward for half an inch. then when stepping on the gaz the knob punches back this half an inch. so much for play in the tranny. you don´t put much pressure on the knob/tranny when you put your hands on it, but after time all those little pressures add up to a nice wear.

it was said that the parts in the transmission are excellently manufactured and quality controlled. yes they are, but all production has tolerances and they never fit those 101%.
 


Top