gu 33 inch tyres

Submitted: Monday, Apr 10, 2006 at 13:57

ThreadID: 32739 Views:9062 Replies:7 FollowUps:10

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brian

Am looking at going up to 33 inch goodyear mtr on gu patrol with 2 inch lift,as these have bigger diameter will this make gearing noticeably higher ??? The patrol already has one of the highest first gears around dont want it much worse.
Anyone with practical experience
Any other considerations?
Thankyou

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Reply By: Scoey (QLD) - Monday, Apr 10, 2006 at 14:27

Monday, Apr 10, 2006 at 14:27

Hi Brian,

I went from a 265/75-16 AT (roughly 31" and a bit) to a 285/75-16 MTR (roughly 33") on my Petrol 80 Series. I did notice a difference mainly up hills, the engine tended to labour a little bit more - the difference was negligible but as after about a week with the new shoes on I was used to it. Hope that helps! The MTR is a top tire!

Cheers
Scoey!

AnswerID: 166165

Reply By: Snowy 3.0iTD - Monday, Apr 10, 2006 at 14:47

Monday, Apr 10, 2006 at 14:47

Brian

On my 2003 Patrol (automatic) I went from the original 265/70R16 to 285/75R16 both Bridgestone (D693 to D694), acceleration and braking suffered a little, but nothing to be overly concerned with. On the highway the revs drop by about 200-300 rpm, fuel consumption may have increased slighlty, I keep accurate figures we are talking maybe an extra 0.2 or 0.3 L/100km. But I can not be sure if it is the tyres alone, as I have done modifications and moved from the Pilbara to SA. Offroad, the extra ground clearance is good.

If you live in SA,WA or Tas, whether or not this increase in size is legal or not, comes down to the interpretation of what an "off-road passenger" vehicle is in the regs which allow up to 50mm increase in diamter. All other states its maximum 15mm.

One question I have for others though; is there any noticable increase in fuel consumption when you go from an AT to a MT tyre, as I am looking at the MTR's myself?

Regards

Snowy

AnswerID: 166167

Follow Up By: Scoey (QLD) - Monday, Apr 10, 2006 at 14:52

Monday, Apr 10, 2006 at 14:52

Hi Snowy,

Driving a Petrol 80 Series, I long ago gave up watching my trucks economy. It seems to vary somewhere between woeful and appalling! Can't help with an accurate answer to the economy question going from AT's to MT's - but at a guess I'd say there's been a slight worsening (I did go up a size at the same time but)

Cheers
Scoey

FollowupID: 421088

Reply By: govo - Monday, Apr 10, 2006 at 15:47

Monday, Apr 10, 2006 at 15:47

Going up to 33's acutally make it feel better on the highway..a few more revs are needed in soft sand..one thing l did notice was that the speedo is spot on now...( got a mate with a GPS to check on day out on the highway )..makes it much more capable off road as well in my opion.
l fitted mtr's 285x16..... 2 years ago and have done 45,000 km ...still have about %30 tread left...most likely will get them again

AnswerID: 166183

Follow Up By: warthog - Monday, Apr 10, 2006 at 17:16

Monday, Apr 10, 2006 at 17:16

3 ltr or 4.2? The 4.2 has 3.9 diffs and the 3 ltr 4.375 I think. I reckon my 4.2 is already too tall in the gearing with 265/75's.

FollowupID: 421115

Follow Up By: Member - Roachie (SA) - Monday, Apr 10, 2006 at 18:11

Monday, Apr 10, 2006 at 18:11

I'm with you there Warthog!!! I'd love to have larger tyres (maybe 315/75s), but even going to 285/75 would be a big issue as far as I'm concerned with the current 3.9 diffs.
I started to look at the possibility of changing diff ratios to 4.11 or 4.375, but it was gunna work out around $3K all up. Probably would have been cheaper to buy a wrecked 4.5L Petrol GU and take the whole axle tube, diffs etc!!!
I have the new Gearmaster low-range gears (not the ones that have been around for a few years, the newer ones that aren't quite as low), so low range is not a problem for me if I had the bigger tyres; only high range.
Cheers
Roachie

FollowupID: 421121

Follow Up By: Leroy - Monday, Apr 10, 2006 at 20:14

Monday, Apr 10, 2006 at 20:14

3.0l has 4.6 diffs. I fink..... but it doesn't have a prob with 285's. Mind you I've had then on the car since new!

Leroy

FollowupID: 421135

Follow Up By: warthog - Monday, Apr 10, 2006 at 22:27

Monday, Apr 10, 2006 at 22:27

I've thought about some 3 ltr centers too Roachie, I didn't realise It was going to be that much. 3 thou prices me out too. I was hoping to buy some 3 ltr centers from a wreckers and hopefully get something back for my 3.9's. The wreckers here don't have any gu's yet, despite many wrecks going through the auctions. They say the wreckers from interstate pay ridiculous money for them, which makes me think gu parts at a wrecker anywhere must be expensive.

FollowupID: 421190

Follow Up By: Andrew (Whyalla SA) - Tuesday, Apr 11, 2006 at 16:58

Tuesday, Apr 11, 2006 at 16:58

$1,000 for new genuine Nissan rear, $700 for new aftermarket non genuine front.
An installed price of $3,000 seems excessive!

FollowupID: 421336

Follow Up By: Member - Roachie (SA) - Tuesday, Apr 11, 2006 at 17:39

Tuesday, Apr 11, 2006 at 17:39

G'day Andrew,
I actually got to the point where I ordered and paid for 2 sets of (used) crown wheels and pinions; 4.11). They cost me $900- for the pair and I thought the install would be maybe $500- all-up, and be able to be done by any local spanner man. That's when the chit hit the fan.!!!! I was advised by local mechanics that this was a specialised area and there were a couple of places in Adelaide that could do it for me. I rang them and was told it would take about 3 days to do and $850- for each (EACH) bloody diff!!!.....

Okay, that doesn't add up to $3K, but I was factoring in the costs of having to hire a vehicle for 3 days; drive down and back to Adelaide (twice each way) plus take 2 days off work in all likelihood.

So, maybe the $3K was a bit excessive, maybe $2,600-.

I got cold feet and phoned the blokes that were getting the diffs for me from Melbourne. They refunded the money to my credit card, less $80- to cover freight!

FollowupID: 421348

Reply By: brian - Monday, Apr 10, 2006 at 18:40

Monday, Apr 10, 2006 at 18:40

To warthog mines a 3litre what do you think ???

AnswerID: 166215

Follow Up By: warthog - Monday, Apr 10, 2006 at 22:18

Monday, Apr 10, 2006 at 22:18

There are others with 3 ltrs who have them and say they are good, Captain is one I think. I have never driven a 3 ltr so I can't say what thay are like gearing wise sorry.

FollowupID: 421182

Follow Up By: Happy GU Owner - Tuesday, Apr 11, 2006 at 16:48

Tuesday, Apr 11, 2006 at 16:48

Brian,

I have a 3 Litre with 285's and I use it as my work vehicle/daily driver. It will be fine if yours is an Auto. Be prepared for tricky takeoffs on a hot day pointed up a steep hill in the manual - unless you have a Dtronic.

My brother in law just put 35's on his and drove it for a little while before getting his diff ratios done, and said that it still drove okay, but needed the ratios doing ( our GU's weigh over 3 Tonne ).

Mic

FollowupID: 421333

Follow Up By: Leroy - Tuesday, Apr 11, 2006 at 21:11

Tuesday, Apr 11, 2006 at 21:11

never had a prob taking off on hills with 285's. Even BIL with 315/75 didn't have a prob.

Leroy

FollowupID: 421434

Reply By: Truckster (Vic) - Monday, Apr 10, 2006 at 22:29

Monday, Apr 10, 2006 at 22:29

Borrow some off someone - its the only way to tell. Others may have a dfferent opinion of what "worse" is ...

It will make a noticeable difference to the point, I ended up doing the diff ratios cause I couldnt handle it anylonger.

AnswerID: 166307