Last night I was doing some spirited driving and went to shift to 3rd but ended up grinding. I found out I’m stuck in 2nd gear. Pulled over and Jacked the car up, found that my shifter rod to be still connected and at first glance, not bent. Linkage and bushings are still attached… When looking directly down at the shifter it looks like I’m in neutral, but car is still in 2nd. I tried pushing it out and nothing, I drove it home and now there’s a slight metallic clicking, similar to an axle clicking, but not as loud. I could hear it clear because I removed the shifters rubber boot. I was reading up and found out that 420G gearboxes up to 12/99 sometimes suffered from damaged arrestor ball guides. Mines 09/99, I haven’t read up on any success stories… If it’s that, would it be best to just buy another transmission?
Yep. You've most likely bent or broken a selector shaft or fork inside the trans. I'd search for a replacement trans; they're not a fragile transmission, so there should be some available. Try car-part.com
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
The G420 is NOT a fragile transmission. My M5's has 267,000 miles, with at least a few thousand of that at full race track nastiness. I'm sorry, but I really don't know anything about "arrestor ball guides", nor have I heard of any failures related to them. If you have, then buy a newer G420.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Also, what fluid are you running?
RedLine MTL; everyone's got a favorite trans oil, this is mine. The OFFICIAL correct (Redline) oil is D4 ATF, some very respected race shops use a cocktail of 1/2 D4 ATF and 1/2 MTL.
Do NOT use GL5 oils in a transmission, they are too slippery.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Do you know what the benefits would be of running D4 atf? I’ve seen some kits with full D4 ATF, MTL, and Mt-90. Mt90 is 75-90w, while MTL is 70-85w. Would running half Atf, half MTL make it slightly thinner, or would there be more added benefits with the additives? I do not track my vehicle as often as I’d like, but I would like to know what is best in the scenario I do eventually go..
If you pour RedLine D4 alongside MTL, alongside Mt90, you won't be able to tell the difference. As I recall, Turner motorsport used a cocktail of MTL and D4. But seriously, I have never found a difference, even in my old E34 M5, which has a fragile and recalcitrant gearbox and a million theories as to why one oil was better than the other.
Like engine oils, everyone has a favorite gear oil, which they swear by...and then say all the rest are junk.
Why do I use MTL over D4/ Because it seems to me that one should put manual gearbox oil in a manual transmission. And, well, all Redline oils are group 5; save the dinosaurs for the gas tank.
Note that "group 5" is NOT the same as GL-5. GL5 oils are for hypoid (differential) use. (Too slippery for proper syncro operation)
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Thank you for that explanation. I ran mt90 in my transmission last summer, it was really smooth. I had tried RP Synchromax for the winter, because I heard a lot of good things from many users. I found that the fluid was alright for about a month, started to feel really notchy, and not in a good way. Car was down all summer due to my ecu taking a crap. I just got it going and I was still on the Synchromax. I can’t say the damage was due to that fluid, but I never found anything good about it, other than the fact I could get it locally. My transmission won’t be here until the 14th, I’ll be going full MTL.. Also, D4 ATF is advertised as manual gearbox fluid too, FCP euro sells its as a kit, but I’m not sure if its adequate enough for high heat. Who knows, maybe I’ll try that when the temps get lower. Thanks
Stickers are gooey paper, and don't make gearboxes work better. Let me clarify: Use D4, or use MTL, or use MT90, or mix all three if you're so inclined, they're really not that different, in the end result.
Now .... automatic transmissions do NOT go by this credo!
Oh crap, here come the grease police, I just stirred up their nest.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Are you saying that the insides of all the same? That they just put different stickers on them based on whether they were shipped to hot or cold climates?
Or, are you saying the insides might be different but in your experience (which I respect) those don't really matter?
Most BMW transmissions use GL-4 oil. Straight from the inter webs. “ GL-4 gear oils are typically recommended for spur and helical gears found in manual transmissions and transaxles operating under moderate speeds and loads. GL-5 gear oils are typically recommended for hypoid gears in automotive axles operating under high-speed, high-load conditions.”
I also read that gl-5 fluids aren’t so good for the metals that make up the synchros. Eventually they will deteriorate if used with gl-5.
As far as D4, MTL, MT90
D4- used in oem and colder climates (70w80)
MTL- Warmer climates to help oil not become too viscous? (75w80)
MT90- Im assuming it’s for race application and aggressive driving since it’s the thickest of the 3. MT90 will take longer to warm up on cold starts too.
I plan on running MTL for the winter, MT90 in the summer
Last edited by Romanleal99; 09-27-2022 at 03:46 PM.
when it comes to fluids for the cars - i try not to overthink it. quality fluids, changed regularly is basically my plan.
my zhp - which has been a street and track car at times in its life - always has had D4 in it. it's now a mostly parked street car so I'll use D4 still but I wouldn't be against MTL.
the e36 track car actually ran D4 for the longest time after it was converted to manual and saw a lot of hard track use. I recently switched to MTL in that car since it sees elevated temps and hard use on the track. If it were still a street car it'd have D4 like the zhp most likely....
I agree with Chris (not that he needs my buy in! haha) - D4/MTL/MT90 or a mix in manuals, go for it. Autos, totally different ballgame...
'95 325iS - auto to manual swap done!
I am simply saying, my friend, that I have tried all three RedLine fluids in BMW G260s, G265s, G280s, and G420's, and, well, I have never felt even the slightest hint of difference. Some of those gearboxes have known weaknesses, some are seemingly indestructible. I've tried all three oils sometimes to try to fix a customer's shifting issue, and , well,none of the fluids made a difference in the issue....or, in a good-shifting gearbox, none of the three made a bit of difference in the shift feel...to me.
But you know, this has now become an OIL thread, and oil threads suck, because everybody is going to turn blue telling me I'm full of $#!+, and some damned fluid changed their life and saved their marriage.
Other than GL5, which absolutely does NOT belong in any manual transmission. And again, I ABSOLUTELY use the exact manufacturer fluid for autoboxes.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Thanks! I appreciate all the insight.
Just installed my new transmission, with Redline MTL. Beautiful, smooth as butter (:
Bookmarks