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Screwed up ZF box!
I'm really at my wits end here! I know there are some transmission people on this forum ! It's a ZF5hp19 box on a 530i.
Ill do bullet points for this : - Previous owner has transmission rebuilt . - The rebuilders do the box and TC exchange, do not open valve body. - I get the car and it has a jerk going from 2-1 when slowing down really fast, it also jerks if I just sit on the brake pedal in drive, and go in manual mode from 2-1. I can feel the transmission shift it, its a really light jerk on idle. Theres also a jerk fromn 3-4. - I think software, so I have it updated, no difference. - I then take it to the people who originally did the rebuild, they have no idea and say its functioning fine, they're too far from me to go again so I just leave it, they do admit they didn't open or clean the valve body, just put it back in. - I then have a reconditioned valve body put in. This fixes the 3-4 issue but the 2-1 jerk is still present. So now whenever I brake hard I get a thump from the back. The suspension has been checked a billion times, it's definitely transmission related this one. Big sigh. |
So you had it's brain reflashed.Given that I assume that adaptations were reset as well.
Reconditioned Valve Body isn't a guaranty that it's refurbished properly. Does it lurch more when it's cold or warm? When I used to have this issue,it was only when gearbox was warm.Now I have a slight kick during the first downshift when I drive it after it set overnight in subzero temps. Check the MAF to throttle body intake book for tight connection. I am wondering if the vacuum leak could cause something like that. Guys mentioned that old spark plugs can have such an effect on the tranny behavior as well. Quote:
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Brain has been flashed buy the bmw specialiasta with autologic, the specialist with gt1 and myself as I have the kit aswell. No fault codes either.
Spark plugs are around 1000 miless old! It happens on cold and warm :( I've checked over the car for leaks but will check again. It doesn't have a BMW battery btw, the car has a different one and it's smaller aswell in size. The thing is, it makes the ever so slight jerk doing it in manual mode when I am sat on the brakes on idle. This slight jerk is exaggerated and felt more when coming to a fast stop aswell then. The important thing here is that it only does the jerk when coming to a really aggressive stop not a gentle stop. Thanks for you reply btw. |
Check your motor mounts. Could be blown. Mine were, and that lurch got even less. I can make it happen sometimes if I really try by coasting really slow on the brakes. But it is minimal at its worst. I also drained and filled my trans two times with ZF fluid, with new OE filters. I still haven't gotten a software update, only because the issues seems to have really gone away. I will get the software update eventually, but no rush.
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Engine mounts are perfectly fine, hardly any movement.
If I coast gently and come to a gentle stop everything is normal. It's if I go really hard on the brakes and stop as hard as I can withoput ABS kicking in then it will feel like a rear ending. Guibo was fine aswell along with the tranny mounts aswell :( The fluid has now gone through 2 changes. Spoke to another 2 tranny people and they both now reckon it's probably something internal and needs taking apart. |
No one got any ideas?
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I would suggest a valve body rebuild,you have a lot of pressure sensitive components in an aluminum housing.Paths get spent,some more play in the shifting valve would bleed the pressure and make shifting/lockup go harsher.
A part of Valve Body in my box was replaced with a new aluminum casting along one of shifting valves(or I don't know how it's called) So,I think it's the fastest and the cheapest way to go in your situation,before you tear the tranny apart. Good thoughts? Quote:
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Already had a rebuilt one put on :(
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One thing I noticed, when stopped and in drive, going from 2-1 makes the slightest jerk, even sat on the brake pedal. I imagine this is the jerk thats exaggerated when stopping.
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I had a rebuilt Torque Converter and it was shuddering,it all depends how well and how "deep" it's rebuilt.If it's rebuilt,but not to specs in some spot,what then?
It's possible.Lazy human factor.You don't simply change the gaskets and springs and check balls inside.You have to measure,now,was that done? Quote:
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