LT230T or LT230Q for heavy Defender 130 Pulse replica camper?

[Tobias]

Hi

I am ready to start the build of the LT230 to go behind a 2.8 300tdi with reinforced ZF Autobox. I have procured the bush for the intermediate shaft and ATB for the centre diff from Ashcrofts.

I have one LT230T from a 1994 Disco 1 and a later LT230Q from a 1997 Disco 1 to use for the rebuild.

I have heard that the gears of the LT230Q are "weaker" but when I now read on the net I find info to suggest that the LT230Q is actually reinforced in some areas compared to the LT230T.

 

Which one should I go for, if I prioritise longevity and reliability. Reduced noise is not unwelcome but also not worth more than reliability.

 

Thanks

Tobias

[FridgeFreezer]

Both will be quite tall gearing for a 130 with a pulse body (especially with what looks like added height on top?), ours (non-Pulse ambulance) is 1.4:1 ratio with a Roamerdrive, and although I can drive it happily most of the time with the overdrive engaged, on mountain roads I think it would not be as nice - and ours has a 4.6 V8 to play with.

With a 2.8 I strongly suspect a 1.4 ratio would be nicer to drive and kinder to the clutch & gearbox, if you manage to get it up to a cruising speed where the engine is revving a bit more than you'd like I'd consider that an achievement.

We were chatting to this guy (right) on the NC500, which is a pulse body with a raised top a bit like yours and a standard 300TDi and they struggled to get above 55mph and were having to drive in low range on some of the steep roads:

 

Not only is it a big heavy old hector, it's a barn door aerodynamically, and pushing that through the air takes a LOT.

[Snagger]

I couldn’t agree more with John.  You really don’t want 1.22:1 gears on that - the 1.4 and overdrive will be a much, much better solution.  Whether you go with GKN or Roverdrive is the better question, as from experience of several on here, Roverdrives do have their issues just as GKNs do.

[Tobias]

Thnaks for the reply, however the question is not on 1.4 or 1.2. Its on lt230t (1.2) or lt230q (1.2), i should have made that more clear  

 

we had a lt230q (1.2) behind a standard autobox and standard but pump tweaked 300tdi in the 130 with demountable camper, that was heavier and taller than the Pulse will be so we are confident we want 1.2. 
i am not afraid to use low range at times. That’s what low range is for - being used! 😉 

we could cruise comfortably at 80-90kph (55mph being roughly 88kph) but steep inclunes saw the speed go down, which is what kick-down is for. 
 

Tobias

Edited November 14, 2023 by Tobias

[Snagger]

We heard the question.  I don’t think you quite heard the answer. 😉

[Tobias]

Which one is stronger? More long lived?

lt230t with original disco 1 1.2 gearset or lt230q with original disco 1 1.2 gearset?

 

Tobias

[hurbie]

i would go with the old spec , and change the collapsable spacer for a solid one .

[bishbosh]

As you have already engaged with Ashcroft for bits I would ask them the question. They will have far more direct and accurate experience than the bunch of reprobates that lurk around here. 

[Nonimouse]

I've had both types you mention and many others. At the moment I have a 1987 RRC LT230 on my Disco

I recon that if you drive them properly, they are all much of a muchness. As you mention, you have no issue with low ratio. This is good. Essentially you have a ten speed box, although some gear differences are more like a splitter than a true ten speed, but they are there to be used. Learning to change up and down the ratio on the move helps.

As for your application, the auto may have issues with not being able to 'find' the right gear, but this is more to do with tyre size than 1.22/1.44 T box. If it becomes a pita simply change to a 1.44

[Snagger]

If you are insistent on the 1.22, then I would use whichever is in better order, and if both very good, then I’d go for the T.  I have heard the same rumour that the finer Q gears are a little weaker, thought they had no trouble behind the TD5 and TDCI, but with the body you are fitting, your battle will be with wind noise, not gear noise - I’d be impressed if there was any perceptible noise difference in the cab between either gear set.

[Tobias]

On 11/15/2023 at 9:37 AM, bishbosh said:

As you have already engaged with Ashcroft for bits I would ask them the question. They will have far more direct and accurate experience than the bunch of reprobates that lurk around here. 

Dave A suggests to go for the older LT230T "with the thicker teeth". So gear strength seems to be the deciding difference here.

 

T

[Tobias]

On 11/16/2023 at 7:03 AM, Snagger said:

If you are insistent on the 1.22, then I would use whichever is in better order, 

Current state of both. 
 

Both housings will get the reinforcing bush for the intermediate shaft and ATB for centre diff. 
the older one will get reinforced intermediate shaft and go to the ambo, as per Dave A’s recomendstion. 
The ’Q’ will go into the missus daily driver 90. 300tdi and auto in that one as well. 
Tobias

[Snagger]

It would have been useful to give the full picture - we could all have been certain in recommending you to keep the Q for the Discovery.  I hope the T works adequately in the ambulance, but I still think it’s too tall for that body and weight.

[Eightpot]

As has been mentioned, assuming you're running a 235/265 tyre, a 1.2 box will be horrid with no upside.  It doesn't just affect cruising speed but you lose flexibility in all gears.  My rangie ambulance has 1.2 gears,  is considerably lighter and much more aerodynamic and isn't pleasant on hills or even pulling away in 1st - I'll be swapping it out when I get chance.  Any fuel saving from lower rpm is lost by having to use more throttle. 

Your pulse probably has lower power/weight ratio than an old army n/a 110 which had to be fitted with a 1.6 box to stop them rolling to a stop on a hill!

 

 

 

[Bowie69]

With a 2.8 and an auto with the torque converter I suspect it may not be as bad as it could sound.

[muzaz]

7 hours ago, Tobias said:

Current state of both. 
 

Both housings will get the reinforcing bush for the intermediate shaft and ATB for centre diff. 
the older one will get reinforced intermediate shaft and go to the ambo, as per Dave A’s recomendstion. 
The ’Q’ will go into the missus daily driver 90. 300tdi and auto in that one as well. 
Tobias

If you get an HD intermediate shaft from Synchro Gearboxes, get a couple of extra o-rings as well. The shaft is an interference fit in the bush and has a tendency to bite the o-ring.