| Author | Message | ||
     Richard Treacy Grand Master Username: richard_treacy Post Number: 2743 Registered: 4-2003 |
In an SY thread the TurboHydramatic 400 (3L80) transmission was discussed, including workshop manuals and the similarities to the later 4L80E. Extolled were the virtues of Ron Sessions’ book on the TurboHydramatic 400/3L80 Transmission fitted to most SY and SZ cars. Incidentally, the 4L80s fitted to RR/B and Jaguars have a special sump pan and gasket compared to the 4L80Es fitted to US cars. That is because the Euro cars have their electrical connections to the rear of the transmission rather than to the side as on US-built vehicles. Just as on 3L80s in Holdens vs RR/B, the guts are the same but the casings differ. This is a follow-up on the subject of transmission overhauls. Since I have had my Continental R, its 4L80E transmission, essentially a TH400 with overdrive, lock up converter and electronic control, has run beautifully. However, the torque converter clutch (TCC) was always weak to engage and I had a few ratio error messages come up on the computer. Annoying also was that, sometimes when using 2nd gear braking down a long hill (namely the Clyde Mountain, the Bulli Pass, the Bateman’s Bay S-Bends and the Berry S-Bends) an error would appear and the transmission was restricted to 1st and 2nd until rebooted. This is a 110,000km car. I figured a new converter would do the trick, but decided to throw in new shift solenoid valves in case the 2nd braking issue was caused by a dodgy valve. Great. Then out came the transmission and it was obvious that the transmission had been visited sometime not long ago. Once opened up it was clear that the transmission had been burned out sometime and repaired as cheaply as possible. Although the clutches and bands were not worn out, there were definite signs of overheating. Likewise, the converter specialist told me that the TCC was ratted from heat. He overhauled it using an uprated TCC lining and the de-rigueur upgrade to a Sonax TCC piston (the original piston in the TCC is a known weakness of the 4L80E). On reassembly I found that the intermediate sun gear had been fitted upside down, so all-in-all I guess that the transmission had been run with very low fluid, burned out, then repaired very cheaply to make the car saleable. That doesn’t faze me as I always expect to have a transmission overhauled and converted to synthetic fluid as soon as I may justify it. While at it, I fitted a new engine rear main oil seal. Do it every time the transmission is out on an SZ or on earlier V8 cars converted to a seal like my T-Series (JF will confirm that the T has no oil leaks whatsoever). Ron Sessions book was a great help for the parts in common with the TH400/3L80, supplemented by the 4L80E-specificbook by Cliff McCormick and published by Atra. Finally, of course I filled it with the very highest-quality full-synthetic transmission fluid, this time from the premium manufacturer Atlantic Oils, an Australian manufacturer of superior oils. That added $300 to the cost: money well spent. You only have the opportunity to convert to synthetic fluid when the converter is overhauled. Likewise, when I overhauled the TC and transmission on my Turbo R I elected full-synthetic Elf G3 Syn. RT. 4L80E Front View  Rear Main Engine Oil Seal  | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2745 Registered: 4-2003 |
Note that the bolt pattern on the generic 4L80E shown on McCormick's cover is quite different from that of a RR/B.  | ||
| Jeffrey McCarthy Grand Master Username: jefmac2003 Post Number: 368 Registered: 5-2007 |
"You only have the opportunity to convert to synthetic fluid when the converter is overhauled." This means I gather Richard that there is no way for me to flush out the Dexon III my guy inserted against instructions without another AU$5000 overhaul/re-build ? | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2748 Registered: 4-2003 |
Well, I don't know where the $5k comes from for a TH400. For those, my favourite transmission shop in Canberra charges a flat $1,200 for a full converter and transmission overhaul plus $300 remove/refit including Dexron III. That includes all bearings, bushes, clutch plates, steels and bands. If the pump or planet gears are cactus you may add $200 maximum as they come from a Holden organ donor. Usually a standard overhaul tops out at $1.500 or $1,800 with synthetic fluid and takes three days as they outsource the converter. Those figures include GST. A 4L80E would add about $800 because of the solenoids, TCC and overdrive. Tops: the UK specialists will charge you UKL850 / $1,400 for an exchange SY TH400 but the shipping is the killer. You will also have to add 10% GST and 5% duty. In any case I detest exchange units as you are sometimes buying someone else’s major problems patch up. On flushing, it is a virtual impossibility. The system can only be fully purged once the converter has been opened up and welded back together. RT. | ||
| Jeffrey McCarthy Grand Master Username: jefmac2003 Post Number: 369 Registered: 5-2007 |
Thanks for that Richard, it's what I thought. I was exaggerating just a little bit with the 5k, I did have the diff and a few other things done at the same time. Still 2 thousand is a fair whack just to change over the fluids; I just wish they'd followed instructions to upgrade it in the first place to save me the trouble of constantly having to check the levels and worry about it, not to mention the service intervals. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 939 Registered: 6-2006 |
Jeffrey, Whatever fluid is in there you will still have to check the fluid level and worry about it. Also, if you look at so called 'sealed for life' transmissions that use these fluids you will find more and more people who have found that the fluid does need changing and if not done they start having transmission faults and complete failures. Even sealed for life boxes should have the level checked . . . but it's awkward and you'll probably need to get a dealer to do it. There is no gain to the owners - but it makes the advertised servicing cost look much betetr. A filter & service here is about £120, so every 4 years (not longer imho) or 24000 miles if sooner, will be a lot less than changing to Synthetic. So although the garage should definitely have followed your instructions, you should not feel devastated about it.  | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2749 Registered: 4-2003 |
Paul, I agree absolutely. Jeff, don’t sweat at all. Synthetic transmission fluid is not at all necessary but certainly nice to have for insane chaps like myself. I still run Dexron III in my T-Series and R-Type and am perfectly happy about that. Hell, these cars have always run superbly and are supremely durable using the fluids available decades ago. I overhauled the R and T transmissions before synthetic transmission fluid was on the market so will stay with Dex III until an overhaul is next required. Over the last month I have run up another 3,000 km in the T and cannot fault it. As implied, most modern cars have no means of even measuring the transmission oil level. They now oversize the filters and use synthetic fluid so that the included 5-year new car vehicle service and warranty require neither attention to the transmission nor to the motor whatsoever. Likewise iridium spark plugs etc. I would suggest that the virtues of full-synthetic motor oils are far more compelling than those of synthetic transmission fluids. I suspect that synthetic motor oils at least trebles the life of a motor. Never having entered a Concours’ I wonder whether there would be penalties applied for such upgrades ?? RT. | ||
| Jeffrey McCarthy Grand Master Username: jefmac2003 Post Number: 370 Registered: 5-2007 |
All good news - I just figured that I might as well have had it done when the transmission was rebuilt. I won't bother changing it now. Anything that extends the life of parts or reduces service intervals and is proven to do no harm is a good thing in my book. And I suspect it'd be an unusual Concours judge who could tell the difference - except perhaps by reading the changed 'Dexron III only' label on the dipstick. The information about new cars having such things as sealed transmissions to avoid servicing as a cost cutting measure with warranties makes sickening sense unfortunately. I just tested the fluid level in the transmission and it seems okay. The shuddering seems to have disappeared on the test drive this morning. I'll take it down for it's scheduled transmission service in a week or two and see what happens. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2751 Registered: 4-2003 |
ps: I was at Supercheap in Canberra last week, and picked up a TH400 filter and pan gasket kit for $5. Yep, five bucks. Unfortunately they told me that the line is unlikely to be continued, so the price will skyrocket to $30 from my transmission shop. $30, about the cost of the weekly carwash !! (shut up James F). |
