AnswerID: 32682 Submitted: Friday, Oct 03, 2003 at 12:40
floyd
replied:
Been there done that priced every option for a HJ 47. The cheapest option is simply to get 33 inch
tyres next time your
tyres need replacing. The upgrade will only cost a couple of hundred dollars more than standards and you get these benifits:
Reduced final drive by about 500 rpm. 100 kms = 1900 rpm
Higher ground clearance for off road
Way better economy
A more useful 1st gear. (you will actually be able to get somewwhere when starting)
Better overtaking in 3rd
No messing around with driveshafts, diffs and transfer cases
Reduced engine noise when on trips (heaps quieter)
I had a 9/84 trayback with the 2H and the 33's totally changed the performance of the vehicle and got me almost 100kms per tank more.
Did come with these negatives but I could live with them:
About 1 1/2 inches higher (not easy for granny to get in anymore)
Speedo was a bit out (15 kms at 100, 8 at 80 and 5 at 60). Can get a new gear to correct this but didnt bother.
The alternative is very expensive and a lot of effort. 60 series gear will not go strait in as some may tell you, diff ratio changeovers is costly and 40 series are so rare to find and not that strong.
Hope it helps.
Reply 3 of 4
FollowupID: 23527 Submitted:
Monday, Oct 06, 2003 at 21:09
Jim posted:
Floyd,
Did your trayback have a four or five speed gearbox?
With the figures you quoted I assume that your truck had a five speed box.
I currently own a HJ47 Troopie with a four speed box and went through the same process as above and settled for the taller profile tyre option in the end.
I fitted BFG All Terrains 33x9.50R15's where I had the stock 7.50R16 which were worn down to a diameter of 31 inches. I worked it out to be a 7% increase in tyre size overall. The result on my speedo and tacho were not that great. In other words when I am cruising at lets say 50 kph according to my uncalibrated speedo I add 7% to this figure which gives me an actual cruising speed of 53.5 kph. The figures rise exponentially as the speed increases, i.e at 70 kph on my speedo I am actually travelling at 74.9 kph and so on. I found that my truck now cruises on the open road at 96.3 kph when my speedo reads 90. This is a good compromise that I have settled with because my 2h is working at the theshhold of being economical still. As soon as I push the girl harder the fuel consumption goes through the roof like a scared cat on steroids. If there is a mild to strong head wind I back off a little to achieve similar fuel consumption results. Remember you are driving a rolling brick with no aerodynamic shape whatsoever and the venerable old 2h isn't the most powerfull of motors. Maybe my diff gears are a little shorter than usual because initially at 100 kph my tacho was reading about 2900 rpm. Now at 100 it sits on about 2700 rpm.
stephen,
Another thing I did to my truck to reduce engine noise was install sound deadening material under the bonnet and on the interior side of the firewall and on the floor between the vynyl. The product is called soundshield and I found it in a popular auto accessory
shop. there are three types, under bonnet, engine side of firewall and under carpet. The first two types are self adhesive and the third isn't. This product helped tremendously in reducing the noise from the engine which made my trucks engine noise acceplable at speed but I stress that it won't be totally effective if you don't cover as much area of the firewall/bonnet as possible. I am considering buying the engine side firewall sound deadener to reduce engine noise further.
FollowUp 1 of 1
