Thread: Rebuilt gearbox subsequent problems ?

At $6.5K, that is very good IMO. You would be struggling to get the 5L40E rebuilt for that price.

Even if you could get some parts made up - flywheel, etc and offer them for sale, I think you would get a few orders from the members here.

Failing that, I would happily throw a few bucks your way for some accurate drawings of what you have done and what needs making.

Also, what are the power and torque specs like on the 5L50E - ie, how much stronger are they?

Keep up the good work - Gav

What are real torque capacities of 5L40 / 5L50?
Wiki says 340Nm/422Nm.
Another site says the 5L50 will handle 25% more torque than the 5L40
Power? Caddys with 5L50E have 230Kw/420Nm
I believe they were also fitted to some Commodore V8's-- don't know the power/torque

Thanks for that. I guess once that's in and sorted, then a power upgrade to the TD6 will be on the agenda?

Almost makes me want to run out and get one so I can chip mine without worrying every time I floor it...

Cheers - Gav

Just a quick belated update from this end,

Had a customer with a Td6 failed trans, had Rhys at Furious performance recommended to me from members on here. After talking with him decided he seemed the best to deal with this and sent the trans up to him in Sydney.

Very happy ended up with a new 5L40 , current internals and valve body so should be longer lasting. After lots of research and discussing with him RE the Sonnax stuff he advised to go with the new trans as the sonnax upgrades don't address other issues in the trans so sometimes not the best solution.

Costs were very reasonable considering new components not reco, and drive in / out was around $8k, including freight etc.

Most importantly happy customer and a very responsive/ smooth transmission I'll be sending my 5L40's to him in future


JC

There's a "reasonable " chance that a power upgrade will happen to the TD6.
Mr Davis special.
I've performed a number of upgrades to Disco Td5's locally ( and my own with a little- extra-again-specia- tweak, compliments of Bruce Davis) )and all happy customers.

The new 5L50E that I used had the benefit of the 2004-2007 upgraded valve block so I think it will outlast me.
The torque converter is higher rated than the std, with 2600rpm stall speed so I shouldn't have to put up with the 3000+ rpm of the old one!

Not long soon!!!!!!!!!!!!!!!!!

Did some reading on this topic and now I’m confused as hell. And sorry I’m sure this has been asked before.

There is the question of upgrades, part numbers for Torque converter changed in 2003 then 2004 and again – I assume the TCC changed as well. I haven’t been able to find anything solid on what and why these changes occurred, or exactly when.
Is there any data on failures by year? Are the first (2002) more prone?

There is mention of two different part numbers for the 5 speed box used in the diesel BMW. A5S360R and A5S390R – supposedly BMW trans part numbers indicate torque capacities 360 & 390nm. Both are 5L40.
Early BMWs (up to October 2002 manufactured trans) had a “Small Diameter” version of the box where the overall diameter of the 2nd clutch and the 2nd coast frictions and steels is smaller (2nd clutch plate outside diameter increased from 130mm in the early models to 138mm) – this is the 360, where the 390 version is the larger diameter. Did RR see the same change? I have no idea what else changed.

Also Stevemfr (GAP fame) wrote a couple of segments (2011-2012) claiming that 99% of failures are pressure related, worn valve block drops pressure to TCC, creating more wear/heat which in turn dumps more debris and wears the valve block further ect ect. We have all read the teardown by RRPhil in which he finds no obvious sign of problems other then the TCC linings completely gone. Both these blokes are well regarded and have expressed opinion that the level of torque produced and weight was not the cause or contributed to failure – it didn’t help but there is other issues at play. ??

I’ve read that the 5L50 has heavier planetary gear set to handle increase torque, but clutch packs and TC were generally the same as the 40, and the valve block is definitely the same.

Don - If you have used the old (40) Planetary Gear set due to the new one not fitting, could we get the same result with a rebuild of our 5L40 using the heavier clutch packs and TC?. With valve issues addressed (essentially what Stevemfr repeatedly claims). Planetary Gear set failures are not common so I can understand why you’re not concerned cutting them out. Certainly not trying to prove anyone wrong mate, just trying to understand for when my goes – we all need someone to do what you have embarked on! As the only local source that has seen both side by side hopefully you can provide input. And for the cost, you’re on a winner..

Justinc - is he providing a brand new trans? As in not rebuilt/remanufactured? What other issues does he talk about?
What is upgraded in the new unit from Furious performance?

Originally Posted by donrover0

The torque converter is higher rated than the std, with 2600rpm stall speed so I shouldn't have to put up with the 3000+ rpm of the old one!

That point alone would be worth it. 2600 would be a huge improvement.

The valve block was updated 2004? any ideas of plate numbers or if we can get an idea if we have an update?

My truck has now done 40,000km with the Bluefin retune (500nm), the trans has been serviced every 20k since I've had it and the fluid comes out clean each time, and there is no noticable difference in operation before/after any of the services like many report (it has always been and still is beautifully smooth) - Now, I'm expecting it to completly self destruct without warning and from what I read it should have crapped out long ago, which has me planning

The biggest wear issues stem from wear in the valve body bores and in the torque converter clutch valve bore!

Harlie
In regards to doing up the 5L40E box with uprated clutch packs the BIG problem is the "direct clutch drum" I mentioned when we first started looking at this. It won't take the torque increases safely if you want to beef the power up. RRPhil has just recently posted about this problem at the end of his 5L40E post ! see link below. The main shafts are different in the 2 boxes

GM 5L40-E transmission teardown - Page 8

Laurie