New 328, trans issues
Reply With Quoteautomatic transmission EH 24001422654 A4S 270R - RX used up to ... — '97, January
BMW lists it as a THM-R1(A4S-270R) which is a GM 4L30e as far as I know.
If it would be a ZF tranny, I would remove the pan, clean the valve body, make a trans flushing, install new balls in the tranny valve body. But I have no experience with the GM tranny.
Diagnosis and troubleshooting GM 4L30E http://de.scribd.com/doc/74302914/Manual-at-4l30e
4L30E transmission servicing tips
Executive summary –
Symptoms:
1.A “lumpy” 1-2 up shift
2.A slow 2-3 upshift
3.The one that bugged me the most – From time to time the trans or torque converter would appear to slip. This occurred when driving under light throttle, engine under 2000rpm and cruising along. If you then accelerate lightly, the revs would rise gradually to about 2400 rpm, but not much in the way of acceleration would be happening. Then at around 2400rpm the trans would kickdown and it would accelerate.
4.Points 2 and 3 never occurred in Power mode.
Cause:
Fluid level wrong (but not as simple as you might think) - The Isuzu service manual suggests that the fluid should be checked between 32 and 57 degC. The same transmission is in some BMWs. BMW say fluid should be between 30 deg and 50 degC. BMW also suggests that the fluid level should always be checked at around 30 deg C and the trans fluid temp should be measured by the OBD2 port. In this way you get the maximum load of fluid in the trans without being overfilled. If you measure it at 50 deg C, then there won’t be enough fluid.
Resolution:
To be done first thing in the morning, before first start and before driving the car anywhere. The transmission fluid must be relatively cool when you start.
Get the bashplate off, set up drain pan, fluid and fluid pump, spanners all ready to go. Start the car, idle for 3-5 mins moving through the gears with aircon on for a faster idle, get the overfill screw off, pump in ATF until fluid started coming out again, pump in another 50-100ml, let the fluid running out reduce to a thin stream and then close up again.
The unabridged version -
Over the last four months, my Monterey has been having some intermittent issues that, for a while, I just couldn’t understand why they were occurring. Specifically there were the four symptoms mentioned above
This all started after a transmission service I did in June. There was absolutely no problem beforehand. At the time, my intial thought was that it was fluid level incorrect. However I checked that 2 or 3 times and it always looked good. For the record, I used a multimeter with a temperature probe to check that the fluid in the pan was between 35 and 40 deg C to get the right level. (You’ll see later on why this is wrong).
I then thought that it was the fluid that was used. At the time I used Caltex Texamatic 1888 which is a Dexron III fluid. Prior to this I had always used Castrol or Valvoline DXIII fluids without problem, so I dumped the Caltex stuff and put in Valvoline DXIII. After this the problems went away to a large extent, but would still pop up from time to time.
Naturally, I wasn’t happy with this as I just couldn’t accept that a perfectly good transmission was playing up after a new filter and new fluid was installed, with apparently correct fluid levels and so on.
So I started researching a bit on the net, in Isuzu, BMW and Cadillac forums (the 4L30E is used in a few different vehicles) and started to find some common problems. Lots of posts with issue number 3 above, with the cars usually around 150000-160000kms, with nearly all of them resulting in a transmission rebuild …groan … not what I wanted to be reading.
I came across one article on a BMW thread talking about fluid levels in the dipstickless transmissions. Not just the 4L30E, but also on a 5 speed Hydramatic and two ZF transmissions as well (the 4L30E is not alone in this no-dipstick world). In it there was reference to a US based European transmission specialist (www.europeantransmissions.com) who published the BMW process to check the fluid level. The instruction was slightly different to the Isuzu process, but there was a key point that would prove to be the silver bullet in my case.
The Isuzu service manual suggests that the fluid should be checked between 32 and 57 degC, BMW say between 30 deg and 50 degC. They say that the fluid level must always be checked at the cool end of normal, ie fluid around 30 degC and it should be measured by the OBD2 port (for reasons that will become apparent later). In this way you get the maximum load of fluid in the trans without being overfilled. If you measure it at 50 deg C, then there won’t be enough fluid.
So about two weeks ago I tried getting the fluid level right using the BMW instructions, but this time it was first thing in the morning before the car was driven. I don't have the ability to read the trans fluid temp via the OBD2 at the moment, so I stuck with the multimeter and probe but opted to target around 20degC at the pan. Get the bashplate off, set up drain pan, fluid and fluid pump, spanners and multimeter all ready to go. Start the car, idle for 3-5 mins moving through the gears with aircon on for a faster idle, get the overfill screw off, measure the fluid temp in the pan – 23degC – pump in what appeared to be about 100ml before fluid started coming out again, pump in another 100ml, let the fluid running out reduce to a thin stream and then close up again. Now go for a drive.
Immediately you can tell the shifts were more positive. Also the slip that I could sometimes anticipate didn’t occur. So I thought let it run like this for a couple of weeks just to make sure that this is the fix.
After the two weeks there was no repeat issues – So I tempted fate and thought, let’s do another service. My reasoning was that I wanted to know if there was any clutch material or metal fragments in the pan after the slipping that had been occuring. So on Saturday afternoon, I did everything again. This time I was using Penrite Dexron VI fluid ($23 for 4 litres at Repco St Peters - I’m sure that price was an error as it's $55 elsewhere – so I bought 8 litres). Fortunately both pans and the servo cover had no trace of fragments so it looks like very little in mechanical problems from these issues. Set the fluid level again, but knowing that the car had been driven earlier in the day I checked fluid level again the following morning. Sure enough, it took another 200ml.
All good now, so went wrong the first time? Well here’s my theory on what happened and what needs to be done in future.
1.This is just a guess, but I think the fluid in the main pan is what is being returned from the transmission cooler. As the ecu is reading the fluid temp from the adapter case, the fluid temp there is higher than that in the pan. Hence reading the fluid temp in the pan would be invalid.
2.At the first service I cycled through 8 litres of the Caltex fluid. I did this by dumping the old fluid from the pan, filling it up with the new, idle the car for 15-20 mins, and repeat until I finished the two containers of new fluid. By doing this, the temp of the trans fluid in the transmission (not the pan) must have gone well over 57deg, leading to seriously incorrect fluid levels.
3.The next morning I checked the level again, but by letting the pan fluid get to around 40 deg, the fluid within the adapter case might have again exceeded 57 deg. So even though more fluid went in, it was probably at the minimum level and still not enough.
4.It would appear that as the transmission ages, it becomes more dependant on having a full load of fluid to operate correctly. It must be at the maximum level without overfilling. So getting it loaded while the trans is relatively cool, not cold, is important. If you have a scangauge or other obd2 scanner that shows trans fluid temp, use it and target getting the fluid level set at 30 deg C. If you don’t have an obd2 scanner, idle for 5 mins or so and set the level. There is probably about a 3-5min window after this to get the level right, before the temp gets to a point where setting the fluid level would be incorrect.
5.Always run the a/c to get a fast idle happening when you are checking the level, to help ensure all fluid passages are full.
6.When setting the fluid level, get it to a point where a thin stream is flowing freely from the overfill hole and close it at this point. If there is no fluid coming out or it’s just small dribbles around the edges of the hole, add a bit more fluid. On the other hand if it’s gushing out, there’s too much fluid in there.
Some other points –
•Avoid cork pan gaskets. They never sealed properly when I used them. The best pan gasket I found is made of duraprene (recycled neoprene) and it’s included in the transmission service kits supplied by ATP. No hint of fluid getting passed these, unlike cork gaskets.
•Speaking of the ATP transmission kit – $55 and it includes both main and adapter case pan gaskets in duraprene material as well as paper servo cover gasket and a filter. I got mine at Auto One at Carlton, however make sure that if they are getting it in for you that they get the kit for the 4L30E (ATP part number FK-1155), and not the one for the Aisin transmission in the 4JX1. Their catalog has the wrong kit listed against the 3.5V6 6VE1. I wouldn’t buy the Repco transmission kit again – approx $70 and you only a cork gasket for the main pan, the paper servo cover gasket, and the filter. They do not supply a gasket for the adapter case pan.
•It’s very easy to strip the threads where the transmission pan bolts screw into the transmission. So have a stripped thread repair kit, like the Permatex one, handy just in case. Also be careful not to overtighten the pan screws or you might distort the pan leading to leaks.
•Be picky with your choice of fluid and never go anywhere near a transmission fluid that says it can be used in all vehicles (eg Nulon Multi Vehicle Trans fluid, etc). Use only a fluid that is Dexron III, IIIH or VI standard. Be aware though that Dexron III and IIIH are obsolete standards and there is no licensing by GM on these fluids. Manufacturers that sell these fluids are no longer obliged to stick to a particular specification however having said that, I doubt that the likes of Penrite, Castrol, Valvoline and other big names would move away from the relevant specification. Dexron VI is the only current GM standard that is licensed, but you need to hunt a bit for it and it can be pricey at around $55 for 4 litres (unless you find it accidentally discounted). As far as I can tell there are only 2 licensed manufacturers in Australia, which are Penrite and Mainline. Castrol claims Transmax Z is Dexron VI compliant but there’s no indication on the packaging of a license number which is a requirement. It’s also quite expensive at over $70 for 4 litres.
•Finally, always have some 14mm aluminium or copper sump washers on hand. We’re fortunate in that the engine and trans both use 14mm sump washers, so if you do your own maintenance then it’s always handy to have a small stock of them.
Here's a couple of reference links that can be useful ...
http://www.europeantransmissions.com....BMW/4L30E.pdf
http://www.europeantransmissions.com...ansService.pdf
from here http://forum.australia4wd.com/index....ervicing-tips/
Originally Posted by shogun
