R380/LT77 and LT230 into a series3

[simonb]

Right then, using a LT77 or R380 to replace the 4 speed box in the series results in the front prop shaft transfer box flange moving back 4" if you use the series transfer box and the Ashcroft conversion plate, assuming you keep the engine in its normal place.

The pics I've seen on here show a 4" long tubular spacer to make up the difference in the front prop length. This also means since the transfer flange of the prop stays in the same place as original, there are no clearance issues between it and the engine cross member of the chassis.

Now if you go the whole hog and replace the series transfer with a 2wd LT230, then the front propshaft transfer box flange moves approx ANOTHER 4" rearwards compared to above. This is because the LT230 front nose on the transfer is shorter than the one on the series transfer (according to my tape measuring this pm.) This makes the front prop needing a 8" extension.

Trouble is engine crossmember is now slap bang in the way if you connect a longer prop direct to the LT230 front flange. So you would need an 8" tubular spacer between the front transfer flange and the prop replacing the 4" one as above.

Question 1:

Will this work (8" spacer)without it all resonanting and vibrating?

I don 't want to start hacking about the engine crossmember as its a new galv chassis.

Question 2:

Those of you on here who have done the LT230 conversion, how did you do yours? Did you keep the engine in the same place or did you move it back 4" so you only need a 4" spacer.

Question 3:

Any of you done this mod in a 88"? With the 5 speed box and series transfer, rear prop needs to be 4" shorter. With 5 speed and LT230, back flange on handbrake drum is only roughly an extra inch or so further back (5-6" total), so rear prop whilst short looks "do-able"

Suggestions and pics please..

[FridgeFreezer]

Well mine is LWB but basically I swung the engine, R380 and LT230 into the chassis roughly where I wanted it and then chopped all the brackets/mounts out and started from scratch.

Fabricated/modified engine mounts

Used RR gearbox/transfer box mounts as they bolt through the chassis so you just need to drill & tube six holes and then it bolts in.

Ditched the Series X-members replaced with a bolt-in Range Rover one, you can get a whole RR chassis with one of these in it for £1.50

Converted the LT230 to 2WD to keep it as God intended

Propshafts are coming from the propshaft clinic because I would have to call in loads of favours to modify stock props and then I'm not sure they'd work properly given the suspension kit...

If I remember to take pics next time I'm under it I will do.

[jericho]

Question 1:

Will this work (8" spacer)without it all resonanting and vibrating?

I don 't want to start hacking about the engine crossmember as its a new galv chassis.

Question 2:

Those of you on here who have done the LT230 conversion, how did you do yours? Did you keep the engine in the same place or did you move it back 4" so you only need a 4" spacer.

Question 3:

Any of you done this mod in a 88"? With the 5 speed box and series transfer, rear prop needs to be 4" shorter. With 5 speed and LT230, back flange on handbrake drum is only roughly an extra inch or so further back (5-6" total), so rear prop whilst short looks "do-able"

1: No to 8'' spacer,IMHO,not even 4'' spacer.Too much weight on prop end of it,causing vibration and bolt failure.

Modify the bulkhead cross member.Ive never seen one rot away at the top edge,which is where you need to cut.

2: I kept my engine in the same place - 88'' 300tdi & lt230.If I were to do it again,I would move engine and box as far forward as possible to shorten the front prop,lenghthen the rear,and give a little more clearance between transfer lever and seat box.

3:Rear prop is do-able.Have a wide angle yoke prop made professionally.It would be best to rotate nose of rear diff up to decrease prop angle a little - reweld spring seats and bump stops where you want them- I have yet to do this.I am currently running with spring wedge/shims,which I don't like, as a temporary measure.I have long/military shackles which make matters worse - without them you may not find rear prop angle a problem.

Best of luck.

[minivin]

I run a 108mm (4") prop spacer on my LT77/Series TC conversion for 2.5k miles with no problems, and that was a full-fat ie no lightening hole through the centre, item that if it was to have been an issue would have manifested itself early on.

I have measured and produced a new drawing to get a new prop spacer made for mine as I am also going LT230 now, I have jigged the LT77 and Series TC, and then jigged and measured a LT77 and LT230, and I have measured bang-on that the spacer changes from being 108mm (4"), to being 7" from mounting face to mounting face. This time however I have hollowed out the item to reduce weight on the output flange support bearings. This should mean that the weight of both items (4" and 7") will be the same, just that the bending moment will have moved out by 1.5".

The rear output flange moves 1 1/8" rearwards comparing an LT77/Series TC conversion to a LT77/LT230 combo. I have not determined how this affects my truck at this moment in time.

n.b. above considers a 20mm thick LT77 to Series TC conversion plate, Ashcroft conversion I believe uses a 12mm adapter plate or thereabouts

[Gremlin]

Some answers from my experiances.

1 a spacer that long sounds like a bad idea, the stresses on the output bearing will probably make it retire prematurely. My solution is the one you do not wish to hear, CUT AND HACK, pics of my jobbie.

2 Engine in the same place, gearbox moved, new props to suit.

3 Mine is LWB so i cannot help much, but i did both props with high angle yokes and longer slip joints. Pics of front and rear.

[Tonk]

when i had the series t/box on the back of the lt77 i ran a 4" ish front prop spacer with no vibe problems, i now run a lt230 and i still run the spacer on the front output, i wouldn't run a longer one though, its easy to scallop the bell housing crossmember to accomodate the front prop on suspension droop whether you run an adaptor or not, i have done both with no problems.

[simonb]

Cheers guys, what ratio LT230s have you got? According to the manual, series TC ratio is 1.148 in high. With a R380 and the series TC, overall gear ratio at wheels is very similar to the standard series main gearbox, with R380 5th being similar to overdive in a series.

With a 5 speed box and 1.4 LT230, 5th is 5.103:1 overall ratio vs series main and transfer of 5.40:1 overall, so if i want to keep the effect of my overdrive I'm going to need a 1.2 ratio LT230 which gives 4.422:1 overall, R380 and series transfer case gives 4.15:1, both of these give approx 20mph per 1000rpm on 7.50 tyres which is the same as all series boxes + overdrive.

Minivan - thanks for measurements, my guestimates with a R380 and Lt230 split on the drive and the series components in the chassis and a tape measure weren't far out!

[MECCANO]

Here is some of mine.. although im doing mine differently

[jericho]

With a 5 speed box and 1.4 LT230, 5th is 5.103:1 overall ratio vs series main and transfer of 5.40:1 overall, so if i want to keep the effect of my overdrive I'm going to need a 1.2 ratio LT230 which gives 4.422:1 overall, R380 and series transfer case gives 4.15:1, both of these give approx 20mph per 1000rpm on 7.50 tyres which is the same as all series boxes + overdrive.

Your numbers suggest you are running 4.7 diffs.You could use a disco transfer box and r380 to get your gearing close to standard series plus overdrive,but you might be better off changing to 3.54 diffs to go with r380 and 1.41 transfer, giving you final gearing of somewhere round 3.816:1 - that is standard defender gearing.

r380 and lt230 with 4.7 diffs might give you a very low ratio high 1st.

[minivin]

nay probs!

I'm going 1.003 LT230 box as with the 3.5V8 it's going to happily pull it, and it makes my revs drop such that in 5th gear I've gained nearly 10mph for the same revs compared to the LT77/Series TC combination. Always important keeping the revs down for the fuel economy

And hopefully my new R380 is arriving tomorrow from Ashcrofts excellent effort by Dave and the team as it's only been a week since I got the parts sent upto them now to get the starboard side chassis mount done as I've already jigged and made the port side mount

[minivin]

This is the ratios that I had/have/will have:

Original series down the bottom with 7.50x16 tyres, 4.71:1 diffs, standard gearbox et cetera.

Top is the LT77 with Sherpa 2WD 1st and 2nd gear (even lower and better crawl speed), matted to a Series Transfer case

Finally middle, R380, matted to RRC 3sp auto 1.003 LT230 and 235/85x16 tyres (31.7" dia compared to 31" dia 7.5x16).

Just hope it all comes together soon as I'm pee'd off not being able to go out on the range at present, since the motorbike objects to speeds less than three figures

[Gremlin]

Mine is a 1.003 with lt77 (56a), 200tdi, 4.7diffs and 31" tyres, It pulls very well and i am very pleased with the gearing. Low range is great as you can crawl obstacles or pull a house down!

It could do with bigger tyres as i do run out of 5th gear sometimes.

GREM

[Tonk]

i run a def lt77 with a disco lt230 1.2 ratio, rebuilt diffs with 4.11 ring and pinions and run 34" tyres, gearing is perfect.

[Pat]

how have people over come the permanent 4wd of the lt77? with a non cv axle?

[Tonk]

the permanent 4wd is in the lt230, i just bought the ashcroft kit, easy and simple to fit.

i've also fitted a lt230 to another series but left it with the centre diff (permanent 4wd), we're seeing how this affects the front axle (read how long the uj's last in the front halfshafts)

[FridgeFreezer]

I also bought the Ashcroft kit, as Tonk said it's simple to fit - there's a guide in the tech archive

[MECCANO]

I fitted rangie axles

[Gremlin]

I run a stage 1 v8 axle

Grem

[simonb]

Your numbers suggest you are running 4.7 diffs.You could use a disco transfer box and r380 to get your gearing close to standard series plus overdrive,but you might be better off changing to 3.54 diffs to go with r380 and 1.41 transfer, giving you final gearing of somewhere round 3.816:1 - that is standard defender gearing.

r380 and lt230 with 4.7 diffs might give you a very low ratio high 1st.

Correct 4.7 diffs, so yes its either to go for 1.2 LT230 or 3.54 diffs (as i thought), then mechanically the transmission is the same as coiler.

So is there any advantage of a selectable 2/4WD LT230 over the standard series transfer? The LT230 will be heavier for a start...

[minivin]

An LT230 doesn't do this to it's Hi/Lo gear system :

I really do not understand why LR didn't increase the length of the dog gear splines to the full length of the gear (rather than under-cutting them within the gear) and then spreading the gear teeth 50/50% between the shaft splines and the Hi gear splines. Would have then increased the gear teeth width from about 1/4" to 3/8" and help prevent the gear from skewing as it so obviously does at present. The above was the deciding factor on me converting mine as I didn't fancy having to replace the transfer case again in the future due to those parts wearing out

[FridgeFreezer]

What Rob said ^^^ also they're a more modern design, one of the few bits LR ever made that people don't feel the need to upgrade/strengthen, and you can get them with different gearing (1, 1.2, 1.4 and 1.6:1). They are also the thing that sits behind an LT77, R380 or Auto box so if you want 5-speeds or Auto you are best off with an LT230.

They used to be more expensive than Series bits but not so these days, and you can pick up good LT230's easier than good Series transfer cases.

With Series diffs IIRC they give you a lower low-box (and high depends on the hi range gears), or you can run coiler diffs for better high range / supposed to be stronger without losing the lowness of low range.

Apart from that, no reason whatsoever