Thread: GM 5L40E transmission Re-built to 5L50E specs

This has been an ongoing job since I got this reply from Wades Garage;

“Your best option as far as I know would be to buy a complete 5L50 for a Cadillac STS or XLR. That will get all of the heavy duty parts in one package. Do some research to find out which one of the Caddy transmissions are closest to your Range Rover as far as case design. Also check which side the shifter stub exits the trans case to attach to your shift linkage. When I did the one for the V8 Solstice, I found 5L40 and 5L50 parts and information very hard to find. But the complete Caddy 5L50's are not hard to find, and all of the heavy duty parts are inside.”
Wade “

The 5L50E is a upgraded 5L40E ! this is a quote from GM Powertrain.

‘The 5L50-E was designed to manage at least a 25 percent increase in horsepower and torque over the existing 5L40-E. Among its host of performance features, the 5L50-E gives drivers the ability to partially override the normal automatic gear selection for greater control when more aggressive driving performance is desired.’

GM Powertrain to Debut New Hydra-Matic 5-Speed

Wear

The 5L40E has some very real problems - nearly all of which are pressure related. In a nutshell, the biggest wear issues stem from wear in the valve body bores and in the torque converter clutch valve bore. It seems that, for whatever reason, the aluminium used by GM in the casting of these pieces is softer than the material used in other (older) GM transmissions. This wear leads to improper shift/lock-up pressures which in turn leads to premature wear in the rest of the transmission components (which drop particulates into the fluid and exacerbate the wear in the valve bores) and, at some point, transmission failure. It is also quite common for the planetary thrust washers on these units to suffer from extreme wear, or even to disintegrate completely.

Valve Body

From 2004 both the 5L40E & 5L50E use the same upgraded valve body. From Transtar Ind.

P134740-1 5l40e 99-01 stamp # 789 BMW w/new ePc & Tcc solenoids/tested
P134740-2 5l40e/50e 02-up stamp # 378 BMW/cadillac shift solenoids w/upgraded aFl/Tcc
P134740-3 5l40e/50e 04-up stamp # 374 cadillac valves

Replacement Valve Bodies.

Europeantransmissions and... price: $480.00 (euro355.06)

http://www.valvebodypros.com/details/5L40E.htm

5L40E Our Price: $329.95

Torque Converters:

Stock: Torque Converters Our price: $240.00 (euro177.53)

Mild: 3 Disc Converter from Precision of New Hampton $250 - $800 depending on specs which you can order.

About Precision of New Hampton Torque Converters

Wild: Level 10 PTS Billet Torque Converter PG, SUPER TURBINE 300, 5L40E, Our Price: $1,098.00

[url=http://www.levelten.com/Level_10_PTS_Billet_Torque_Converter_p/gmct-gm310-9730.htm]



Heavy Duty Rebuild Kits:

BMW | Cadillac 5L40E Transmission Rebuild Kit $759

134006A Master kit, 5L40E / 5L50E- 4 wd (AWD) *Email for availability
2001 - Up 4 wheel (AWD) drive For cars made for the USA market! Bonded pistons are NOT included

GM RWD Transmission Parts 5L40E, 5L50E Transmission Parts Makco Transmission Parts

Oil Pumps

The sump capacity in the 5L40E creates problems with pressure also.

http://www.sonnax.com/system/pdfs/14...pdf?1289926276

An upgrade to a Sonnox unit would be a good start. A Level 10 PTS Bulletproof, SUPER TURBINE 300, 5L40E $398.00

[url=http://www.levelten.com/Level_10_PTS_Super_Pump_p/gmct-gm1400-6120.htm]

Thrust Washers

Use of these thrust washers, now makes it possible to reclaim previously unserviceable planetary units, considerably reducing rebuilding costs.

Automatic Choice, New Parts

As you can see local prices are a bit stiff even for allowing freight from O/S; there are other sources for parts, I just used the above sites for cost references. Just to confuse things GM recommends Dexron for the 5L50E, I think I would still use the good oil just for peace of mind.

The only way I suppose to be sure is to get someone to try and rebuild a 5L40E to 5L50E standards.
Any takers ???
Laurie

Hi Laurie

Did you ask Wades about building a box. ie sending one over and have them rebuild it with all the good bits done.

Gary

Would be good to try and get some pictures of the two boxes side by side - if not much difference, would it be feasible to just fit the stronger one? Also, they mention that post 2004 5L-40Es had an upgraded valve body - are post 2004 td6s hence more reliable, gearbox wise, than pre '04?

Am looking to get a l322, but the gearbox issue on the td6 has me a bit worried.
Thanks!

It seems the vast majority of TD6 owners are completely unaware of the problems these transmissions have.
All the owners that i have talked to are horrified when i tell them that the box is sealed for life and that it will most likely fail at 150k ish.
They all seem to think LR servicing takes care of the box.
Come on LR and get with the programme and service these things at 60k intervals and stop damaging the brand.

Yes LEO i agree with your last comment

Given the sheer size and scope of the USA modification/hop up/ hot rod/street machine industry, I would be surprised if you can't find a number of shops already doing this trans. modification and rebuild.

Google auto trans shops & Los Angeles and see what arises.

Gary
No I didn't ask Wade about a rebuild,the freight both ways plus the rebuild seemed like it would be too expensive.

Leo
A bit more digging and I have found this from fullfatrr !

The later L322 TD6s may have been fitted with the upgraded transmission ?
as there were actually 3 different LR part numbers for the Torque converter. The very first had one part number which was quickly superceded.
This part was then in turn changed for MY04, but has since been obsoleted and superceded back to the previous version, so there is now only one LR part available part for all TD6.
If this is right, LR was trying to avoid future warranty claims, by upgrading the box "good", BUT trying to avoid admiiting they had a problem in the first place "very wrong move against customers"

Just as a side note BMW won't repair these boxes, they instead willonly replace withan updated remanfactured unit; can be had O/S with 3+ yr waranty.

http://www.automotix.net/transmissio...inventory.html


In Australia BMW X5 and Holden VE & VZ Commodores had the 5L40E auto so it is a local box also, so some local Auto Trans people would have to know how to beef it up for the local street racers.
The load rating was partly why GM only used the transmission for only 3 years!!! This auto was replaced by the 6L50/80/90E variants in nearly all local GM vehicles. MAYBE tip the five speed and put in a 6 speed if it FITS.

Brian
Finding a shop is not a big problem,it's making sure their auto specs matches the Rangie specs eg transfer box mount etc. The BMW rebuilders might be a good source of info too. I'll have a look at this later .

The LR, BMW, and Holden boxes are all slightly different, even inside, so most parts are not interchangeable.

As some of you know, I have been researching this because my trannie failed last week.

I looked at a few options from the US, but by the time I added freight, duties and taxes, this added over $1,200 to the cost, and this made it about the same price as getting one rebuilt locally.

Most of the recoes I rang up about only had a 12 month warranty, and when I asked what they replaced, they all pretty much said they replaced what was broken, so not a full rebuid.

It is now on its way to Sydney, to a place called 'Furious Perfomance'. They offer a 3 year warranty - can't remember but may have been 60,000km.

They rebuild the torque converters and pump themselves, and also use upgraded parts in the valve body from Sonnax in the USA. I will post the results when i'm back on the road.

Cost wise, they are very competitive. I have been quoted between $3,300 and $14,000 for a replacement, and these guys come in at $5,000 drive in drive out, but will be cheaper than this as I'm sending them my box. By the time I add labour and new trannie cooler and lines, around the $6,000 mark, which is expensive, but I end up with something that has the same warranty as a new box.

Time will tell I suppose,

Cheers - Gav.