The question has been asked so many times I thought it was about time to give this a go.

Most know there are differences in how the TJ and the TL set up works with the deletion of the speedo drive on the TL (using the output shaft sensor to drive the speedo) and thus if you put a TL box into a TJ (or other way around) it will go into limp mode.

Given this, as we have our wagon loan car stripped back to a shell for upgrades I decided to throw a spare 380 5sp Auto into it (thought will make the Ralliart Motor more worthwhile) and see what happens

Have not driven the car on the road as such yet however have done workshop tests and found it is changing gear smoothly, speedo is not an issue and is not going into limp mode so all is looking very good.

What does this mean? Given we have upgraded ALL of the TF exec systems to TJ (SRS, ABS, Elec Windows, Cruise etc etc) this now means that for anyone with a 5sp Auto in a TJ that dies we are able to fit the 380 box in its place. There will be an ECU and some loom upgrades required however stock permitting will not be an issue.

For anyone with a 4sp Auto in a TJ we can also do an upgrade to the 380 5sp Auto box for those not interested or able to change to Manual but still wanting the 5sp Auto

TL/W owners are one step better off if they have a 5sp Auto already as it is plug and play, 4sp Auto owners will need some upgrades in so far as ECU and Looms as well but is much easier to do with the TL than that of the TJ

The 380 box has proven to be much more reliable than that of the TJ - TW box, in 4 odd years we have replaced perhaps 3 transmissions in 380's total and 1 of these was because of a poor casting on the transmission casing causing a very slow fluid leak.

If anyone is interested, please call us for prices, we have stock of the boxes, the ECU's and looms will be what we are limited on stock with.

What are the 380 gear ratios like compared to the 3rd gen 5 speed?

What are the 380 gear ratios like compared to the 3rd gen 5 speed?
I wasn't able to find much via Google, but it appears that 5th gear is 0.69:1 (vs 0.73:1 in the Magna 5 speed) so I'd anticipate the rest of the ratios would fairly similar, however the final drive ratio appears to be 3.33:1 compared to 3.685:1 for the Magna 5 speed. That would lower the highway/freeway cruise revs noticeably - quick calculations suggest a bit over 1900rpm at 100kmh compared to about 2250rpm for the Magna 5 speed... if I didn't have an AWD I'd be quite interested in such a swap :hmm:

I'm looking forward to Mal's road test results, particularly in relation to torque converter lockup in 5th; while I don't expect there would be any issue with a 6G75 or a near Ralliart spec 6G74, based on my recollection of lockup behaviour with a stock 6G74 (admittedly with the heaver AWD) I'm wondering whether it would have the necessary torque at those revs with the stock torque converter to trigger lockup. Unfortunately the torque converter control parts of the TCU code still elude me...
:swearing:

Would be the way to go when the 4sp packs it in, may as well get the 6g75 at the same time.

Wow, this is awesome news. I have a question about KL/W AWD; can they take the 380 auto as well?

Given this, as we have our wagon loan car stripped back to a shell for upgrades I decided to throw a spare 380 5sp Auto into it (thought will make the Ralliart Motor more worthwhile) and see what happens


The world needs more people who are willing to experiment like this - and publish the results - Great work Man - looking forward to the road tests.

What are the 380 gear ratios like compared to the 3rd gen 5 speed?

3rd gen ratios: 3.789, 2.057, 1.421, 1.000, 0.731. FD 3.684
- - -380 ratios: 3.789, 2.162, 1.421, 1.000, 0.686 FD 3.325

3rd gen overall: 13.96, 7.58, 5.23, 3.68, 2.69
- - -380 overall: 12.60, 7.19, 4.72, 3.33, 2.28

With a 5 speed auto 3rd gen, converting to a 380 auto would lower revs at 100km/h by close to 350.
In the case of a 4 speed 3rd gen it would only be about 100 (the 4 speed having a higher FD that the 5 speed - in fact slightly higher than in the 380).

Unless you're changing the FD ratio, the top-gear difference would only be between the 0.731 and the 0.686 (i.e. 6.6% - or about 137RPM @ 100kph).

Unless you're changing the FD ratio, the top-gear difference would only be between the 0.731 and the 0.686 (i.e. 6.6% - or about 137RPM @ 100kph).

But you would be changing the FD because - unless I'm very much mistaken - its integral.

In case anyone wants the 4 speed ratios, they are 2.842, 1.495, 1.000 & 0.731, so the top 2 are the same as in the 5 speed.
However the FD of 3.269 gives overall ratios of 9.29, 4.89, 3.27 & 2.39.

this is v interesting for if and when the 4sp in my TW ES dies. Some Q's:
-will the tiptronic shifter still work the same way?
-what will the 1-2-3-4 indicator on the dash do? (altho' I could live without this)
-could my local mechanic cope with the loom and ECU issues? ie, how hard are they?
or could I put in a 380 ECU? would this work with the 3.5?

Any update on this car, Mal?

Can a 380 engine & transmission be removed & installed in a Magna as a single unit?

Have any 380 owners had auto issues (other than the cases Madmagna referred to)?

Interesting. Are the 380 tiptronic shifts quicker than a 3rd gen 5 speed? What's a rough price for a 380 VRX swap?

Still playing with the car.

2 issues only are the speedo is reading about 10km slow, this is at 60 80 and 100 so a needle move should get this about right. Other issue is change from 2nd to 3rd, sometimes is laggy others is a thump, I think I was unfortunate that the trans I used had been sitting for a long time and add to this was not in the best shape when it comes to the fluid we drained out of it. Have more boxes here so I will pop another in when I get a chance and then see if it is different, if not then short of making a trans programme to suit then it will not be doable.

Had to try to find out, I am hopeful the change issue will be just this particular box as all other gears are so smooth and responsive.

I'm going to bump this as it seems more appropriate than starting a new thread. I have a KF FWD and want to do the 6G75 swap when the time comes, instead of just replacing the timing belt. The first 2 gears in the 4 speed are very long in the tooth, noticeable drop in power when shifting from 1st to 2nd and I can tell the gearbox slows the car down massively. I wanted to go 5 speed at the time but have heard the top gear cruising rpm is significantly higher, madness IMO. So it seems a 380's gear ratio's are about perfect

But the real question is whats necessary?
And while I don't expect an exact quote, what would be a rough difference in price in just going for a 6g75 + early model 5spd vs 6g75 + 380 gearbox with all the required bits

Given you have a KF the work involved to get everything back up and running again including your cruise control etc is mammoth, to be honest unless you have very deep pockets you are better off going manual or a better trans 4sp auto

What do you mean by better 4spd auto? As in one from another car? Or are there different gear ratio's amongst the 4 speeds?

But 6g75 is no problem in a KF right? Since there's quite a bit more torque down low with that engine, it may be fine with the 4 speed I have...
Alternatively, is it possible to alter the gear ratio's in an automatic transmission? I have very little understanding of how they work, but if they ultimately drive multiple gears, is it possible to swap the gears for 2nd and 3rd with higher ratio ones. I don't mind having a big gap between 3rd and 4th since 4th is only ever used for cruising, but the massive gap between 1st and 2nd is just crap.
I wouldn't want to alter the final drive ratio since it would have to be way off where it currently is for 2nd to be viable, then it'll be cruising at 3000rpm in 4th

6G75 is not an issue, it is the controls required for the 5sp Auto thus why if your current 4sp auto is getting tired is better to try and get a lower k one or yours rebuild

Sure you can change gearing if you really want to but how deep are your pockets as they will need to be real deep.

Well its a bit of a bummer that I can't swap the gearbox then. It's perfectly fine no issues and very smooth, but as i'm sure you know 1st will do about 70-80kph to redline and 2nd does around 160kph. Utterly stupid gear ratio's

If the car wasn't in such great condition i'd just get a later model but I can't justify that. Very unlikely i'll get one thats been treated as nicely, has no squeaks/rattles/vibrations etc

Thought this was the right place to ask this question - do the magna drive shafts need to be changed if a 380 gear box is fitted or do they fit directly? Thanks Ron