70mph=3500rpm whats wrong?

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the hammer

the hammer

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arsehole of lancashire
hi all i have a 94 300tdi disco with an issue,70mph on the motorway its doing 3500rpm with not alot of power left,new parts recently brake calipers,both props,recon injecters,lift pump,clutch. i have cleaned out sedimenter today aswell as check there is no resistance on the hand brake but it is fine,it also judders on take off and when decellerating it can kangeroo and bang(not back firing)sounds like from rear end.any ideas would be most helpfull as i will be towing my caravan next month
 
Has it always revved this high or just started? any modifications? Revs at 70mph :)eek:) on my manual 300 tdi are just over 2000 and so should yours be. I assume you are using 5th gear?
 
my disco 95 on a m reg 300tdi also revs about 3700 to 3800 at 70mph seems very high and i constantly have to check im in 5th gear ! but i can't find any charts/tables for gear ratios to check if it is normal :confused: is there any where i can find more info on rolling gear ratios ie axles/gear box
cheers John
ps tyre sizes are 235/70/16.
 
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Have a look on the back of your transfer box and see what the lable says, it should be 1.22 ish to 1
if it's 1.4 to one then that's yer problem.

think that's right although my defender used to be about 4200 at 70 but that's with lt 85 and 1.4 transfer box.
 
this is often caused by the wrong sized pulley on the alternator for the year of car - as the rev counter runs from the alt speed a small size difference can make a lot of difference.Many sellers (especially on ebay) will say that "this alt fits all 300tdis".....well,it does fit,but it buggers your rev feedback.
 
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