What is the Proper Transmission Fluid Change Interval for a 5 Speed Manual ?

[Truckeeskibum]

I'm getting close to finishing the post-purchase/known problem to do list on my Z - a 1997 1.9L with the 5 speed manual.

Seat bushings, glove box, floor mats, HVAC lights and new stereo are done. Oil filter housing gasket, new belts and new windshield washer pump will be done this coming weekend. The wife and I are currently debating between the Wet Okole and Iggee seat covers.

I one final thing I am looking at is changing the transmission fluid/oil. The car feels a little stiff and difficult getting into 1st gear in my opinion, but I don't have a good frame of reference with the Z and I'm still a little rusty with the left foot since I haven't owned a manual transmission car for 20 years.

The original transmission was replaced at 44,000 miles in 2002 by a BMW dealership. Apparently there were some issues with the original unit.

So, it is now 17 years and about 40,000 miles later. The cost of a couple of bottles of Royal Purple Synchomax is minimal, but given the relatively low miles on the replacement transmission, would changing the fluid likely to make any difference, or I am just not used to the feel of the BMW 5 speed.

Any opinions would be appreciated.

[ZGator]

A lot of people here like Amsoil - but it's like politics - everyone has opinion - I think it improved shifting - I have add it in at least 5 years now, back of my mind I think I should change it.

One other thing to try is to bleed the clutch slave cylinder - brake fluid.

[zellamay]

Nothing wrong with changing the fluid, but it could be something else causing difficulty going into first. If you have clutch stop on the floor, take it out. The stock clutch lines sometimes expand under pressure, so people put in a SS clutch line. (That is hard to diagnose unless the line has obvious cracks or lumps. I think some people change it just to make sure. I still have the stock one at 113K) ..... Have you ever found the reservoir low, or is it better after warm up? (air in line) Is it worse if you hold the clutch pedal down for a minute (slave cyl) Do you know anything about the history: was it once better than it is now? how long has this been going on? ..... I have used Royal Purple and Redline in different cars, with good results.

[colb]

BMW would have you believe that the gearbox is a filled for life unit, changing the fluid is a good idea based on mileage or years of ownership. Check your owners manual for type of fluid yours takes, some use ATF. There would have been a label on the side of the gearbox to indicate what it should be filled with. Easy job to do, just make sure you can get the filler plug undone before draining the box. I use a funnel with a long plastic tube attached and thread it down through the engine bay and into the filler hole when refillling. Refill untill it flows out from the filler hole. Box takes about one and a half litres of fluid. Choice depends on what you want to pay. Well worth doing as it transforms a knotchy gear change with fresh fluid in the box.

[Truckeeskibum]

I bought the car in November 2018 and put it into hibernation for the winter. I'm just getting the chance to drive it regularly after a constant barrage of rain and snow throughout May. So I don't have much personal history to know if there really is a problem or not.

This was Memorial Day Weekend. Not driving the Z.

IMG_0055.jpg


I am the third owner. I have most (if not all) of the receipts from the two prior owners. I'm pretty sure all maintenance has been done by the original dealer or a couple of independent shops. The 2nd owner didn't strike me a someone who wrenches on his own vehicles. The car is completely stock and I am pretty certain that the clutch line is original.

I will try to see if there is a correlation with warm up and time that the clutch pedal is depressed.

[Randy Forbes]

According to BMW's guidelines, it would be at the beginning of the xmsn's 2nd lifetime

All three (3) of my 5-sp BMWs still have their MTF-LT2 in them (95k, 67k & 48k miles, respectively). I've put, at owner's requests, Amsoil, Royal Purple and Red Line fluids in, but other than short test drives, can't say authoritatively that any of them left any impression on me.

If you're looking for oil change interval rates, I'd recommend that you contact a representative of the oil of your choice__we already know BMW's stance on the fluid the car was shipped with (subject to debate as what constitutes a lifetime)

Zellamay makes the best argument, that of the hydraulic circuit causing you problems. While on the face of it, bleeding the clutch is simple, but there're tricks to doing it right (there're dealerships and independent shops that haven't truly mastered it...) so read up on that. The rubber hose does expand, wasting some of the pedal travel, so a swap to a ss/Teflon hose almost always makes an improvement (get one from Rogue Engineering, not UUC).

Getting the clutch hydraulics properly sorted, and some practice on your clutch-leg are probably all you need.

[Vintage42]

... All three (3) of my 5-sp BMWs still have their MTF-LT2 in them (95k, 67k & 48k miles, respectively)...

The factory fill was apparently MTF-LT-1. Did you mean to say your cars still have the original lifetime fluid in them? Or that at some point you replaced that with the successor fluid MTF-LT-2?

MTF-LT-1 sticker.jpg

[Randy Forbes]

The factory fill was apparently MTF-LT-1. Did you mean to say your cars still have the original lifetime fluid in them? Or that at some point you replaced that with the successor fluid MTF-LT-2?

MTF-LT-1 sticker.jpg

I got "MTF-LT2" by looking at the gallon jug on the shelf, the cars would still have their original fillup in them*.




* the Coupe's had a replacement xmsn fitted during its prior ownership CPO period , presumably because they couldn't successfully perform the shift-pin SIBs, so depending on when LT2 superseded LT1, it could have either one...

[rf900rkw]

The OP has a 97, 1.9. That would be a Getrag 260 that came filled with plain old Dex-3 ATF. And that is what works best in it.

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I got "MTF-LT2" by looking at the gallon jug on the shelf, the cars would still have their original fillup in them*.

LT-1 was superceded with LT-2. You can thank LT-1 for all of the shift pin service work you've done. Boxes that came with ATF ot LT-2 did not suffer the fate. LT-1 had an additive that attacked the teflon bushing lining.

[zellamay]

Is there any way to know by year/model whether mine originally had LT 1 or LT 2 ?

[Vintage42]

The OP has a 97, 1.9. That would be a Getrag 260 that came filled with plain old Dex-3 ATF...

Which as you said is now known as Dex-Merc:
https://www.bimmerforums.com/forum/s...7#post29044737

[rf900rkw]

Is there any way to know by year/model whether mine originally had LT 1 or LT 2 ?

LT-1 showed up around 1998. LT-2 replaced it in roughly 2002. I have not seen a Z3 with LT-2 from the factory, but that doesn't mean they didn't exist.

[zellamay]

LT-1 showed up around 1998. LT-2 replaced it in roughly 2002. I have not seen a Z3 with LT-2 from the factory, but that doesn't mean they didn't exist.

That might explain why 3rd is sometimes hard to find, especially at high rpm. I don't slam the gears or power-shift. I've gotten more skilled at it, so it's okay, but not as good as it should be.

[rasmuw]

That might explain why 3rd is sometimes hard to find, especially at high rpm. I don't slam the gears or power-shift. I've gotten more skilled at it, so it's okay, but not as good as it should be.

I have a similar 3rd gear issue. The gear doesn't find itself when pushing forward from 2nd, but I have to guide it into place.

Maybe it's me. Shouldn't neutral be found between 3rd and 4th, like every other 5 speed I've driven?

[rf900rkw]

Which as you said is now known as Dex-Merc:
https://www.bimmerforums.com/forum/s...7#post29044737

Unfortunately nothing stays the say. Some of the oil companies have been pushing the limits on viscosity while still labeling as compatible with the old specs. For intance, Valvoline Max-life hasn't met 71441 specs (older ZF) for some years, This is per the product spec sheet, though the bottles still claim it does. Now days, look specifically for Allison C-4 and Caterpillar TO-2 rating.

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I have a similar 3rd gear issue. The gear doesn't find itself when pushing forward from 2nd, but I have to guide it into place.

Maybe it's me. Shouldn't neutral be found between 3rd and 4th, like every other 5 speed I've driven?

You have the classic shift detent bind. Yes, the shifter should sit positively in the middle of the 3-4 gate when in neutral. There are 4 bushings that need to be addressed, but most only address the two BMW offers a kit for.

[rasmuw]

You have the classic shift detent bind. Yes, the shifter should sit positively in the middle of the 3-4 gate when in neutral. There are 4 bushings that need to be addressed, but most only address the two BMW offers a kit for.

I did some research on this and have gotten thoroughly confused with the words bushings, detents, and pins. Can you be more specific?

[Randy Forbes]

I did some research on this and have gotten thoroughly confused with the words bushings, detents, and pins. Can you be more specific?

This is about the midpoint of the job...



These are the two (2) bushes Randy W. refers to as being in the BMW kits__and historically, the only lazy lever ones I change, though I'm as curious as you to learn what the other two (2) are! They are the spring-loaded resistance one must overcome to engage 5th & reverse gears. Randy W. has developed fixtures and tools to get the xmsn apart without imparting further damage, so he's able to get at any bushing, bearing or gear at will (wish he'd post a picture once in a while...).



There are three (3) other bushes/pins to be upgraded at the same time, their caps along the top of the box seen here, though they're covered in a separate SIB. The symptom of which being difficult to engage 1st/2nd gears when the box gets heated up.

[Vinci]

All lubricants are "lifetime" in their application. Once the lubricant fails, the lifetime of the lubricated part ends. The idea is to replace the lubricant before it fails so that the part's lifetime isn't dictated (exclusively) by the lubricant.

Randy W. has developed fixtures and tools to get the xmsn apart without imparting further damage, so he's able to get at any bushing, bearing or gear at will (wish he'd post a picture once in a while...).

Those tools would have been handy about 8 or so years ago when mplazz and I tried to replace the rear case on his coupe's transmission. We spent about a week fabbing tools and studying the ZF manual trying to get it apart before we made our peace with not having the tools to do it right. Still a fun project...

[rf900rkw]

All lubricants are "lifetime" in their application. Once the lubricant fails, the lifetime of the lubricated part ends. The idea is to replace the lubricant before it fails so that the part's lifetime isn't dictated (exclusively) by the lubricant.

We're at the point, have been for twenty plus years, that it works the other way around. The fluids and additives are so good that they will outlast the component.. If the fluid is bad, it's because the component failed and contaminated or cooked it.

[rf900rkw]

These are the two (2) bushes Randy W. refers to as being in the BMW kits__and historically, the only lazy lever ones I change, though I'm as curious as you to learn what the other two (2) are! They are the spring-loaded resistance one must overcome to engage 5th & reverse gears. Randy W. has developed fixtures and tools to get the xmsn apart without imparting further damage, so he's able to get at any bushing, bearing or gear at will (wish he'd post a picture once in a while...).

Yes. There are three springs controlling the cross-gate movement. The first is an internal clock spring that pushing towards 5th. Second, the top one in your picture, is a heavy spring on a stepped detent that keeps you out of the reverse gate. The third, the bottom one, keeps you out of the 5th gate. It has to overpower the clockspring, plus a bit more for feel. They both stick badly, but it's the bottom one everyone notices. It makes 3rd hard to find, and gives you the 5th gear lean. The Getrags of the era, both 260 and 420, suffer the same problem. But they have a mechanical stop for the clock spring so it can't shove the shifter all the way over; no 5th lean. That and BMW doesn't make a repair kit makes people think there isn't an issue. There is, it's just different symptoms.

The other two bushings are under the third cover you don't remove. This detent controls the fore/aft movement of the main shift rail, with positive detent positions for forward and back, and less for neutral. The "snick-snick" you should feel. This detent plunger is smaller diameter and much longer, using two bushings. It's usually a royal bastard to pull out since it's deeper in and you can't grip it with snap ring pliers. Then you have to deal with the two small bushings way down in there, positioning them exactly without damage. PITA to do, but it does improve the feel of the shifter.


As far as the three on top, I have never seen the wear BMW describes. I suspect this is an old issue, since the base design has been around since the mid 80's. All of the hard to engage issues I've seen have been clutch induced, usually the flex line.



When I'm working, I'm working. I don't think to stop for pictures.

[Randy Forbes]

Thank you for that. I had suspected that the 3rd cap on the side had to do with fore-aft shift-shaft travel__it looked to be in the ideal place for it, but was never curious to find out__I'm glad for that, because I would've gone after the bushes, possibly making a mess of it (I presume the bushes are available, I didn't look...).

I've encountered one or more of the pins on top hard to remove, but never really stuck. I have come across a car that had a top cap missing! I've also encountered the top bushes where they'd already been replaced, but were shedding their coating (remove them with some difficulty, eventually tacking a TIG filler rod to their top flange and using a Vise-Grips equipped slide hammer).

When I'm working on a customer's car, it's a reflex action to document everything with pictures__A LOT LESS explaining to do when presenting the bill__but when I'm working on my own stuff, I WISH that I'd gotten some pictures for future reference. I really have to make an effort on my own projects, if I want to see how I did something in order to repeat it again later!

Thanks again for the clarification. BTW, Jay McA. was here last week, and he spoke very highly of you when helping out with his M3 project(s)! Unfortunately, the engine that I was supposed to just swap out rod bearings on, turned out to have eaten an oil pump (!!) so retirement has been postponed once more, to build another S54. One of these days...

[rf900rkw]

I failed to mention the biggest issue with installing those two bushings is not only do they have to be in the right place, they have to be aligned to each other. If you do attempt it, make yourself an aligning/sizing/cleaning tool. If memory serves, which happens less and less, it's nominally 12mm. So a chunk of something hard (I used 4130, I think) turned and polished to 12.0xmm. Half the time you don't need to change the bushings; just run the sizer though them.


Removing old bushings. Tap and slide-hammer.



Jay is definitely a character. I tried to get him to drive my supercharged S52. But he seems determined to stick with those pesky high strung S54s for his track car.