BUGA Community
Technical => Driveline => Diffs => Topic started by: mezzmo on February 26, 2009, 01:37:22 PM
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Hey fellow Bedowines!
I need some information on Diff ratios's please. My 76 has a 173 or 179 (not sure which) and 3 speed auto, the motor is strong, the tranny is solid but my god is it sluggish and screams in top gear!! Question:: has anyone any information as to what ratio i would need to quiet down and substantially reduce the top end high revs and what would i sacrifice with the replacement - as the theory goes - every action has a reaction! but i cant imagine it could be any worse than what i have.
I have actually purchased a VN to do a transplant to a V6, but to be honest, i would be perfectly happy to retain the old red if i can fix this issue.
All help greatly appreciated - (also please keep in mind that i dont possess an ounce of mechanical ability so please explain in english if possible!!!)
Mezz
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Mezz
Basiclly the diff ratio is a number that represents the number of revolutions (turns) the tail shaft (and thus motor) has to spin to turn the wheel one full turn.
Bedfords origanally came with a high ratio diff 4.2:1 that was good for round town weight carrying in England. Not really designed for Oz conditions.
Common ratios for beddys and holdens in Oz are aprox 3.5:1, 3.25, 3.08:1 2.75:1, you often see these refered to as Highway diffs.
In your situation it seems you more than likely have a original ratio diff (4.2:1).
You can either get the diff center replaced with a different crown wheel and pinion or find a replacement diff.
If you do a search on this site there are quite a few threads on Diff ratio's.
Try looking at This One (http://www.buga.com.au/index.php?option=com_smf&Itemid=2&topic=391.0) for a start.
Note that these ratio numbers are from memory, and may not be 100% correct, but you should get the idea.
Warren
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Cheers Warren - really helpful info on that link.
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Mezz, have found the 3.5 to be the best behind a 202 the cresta gears fits straight into the centre of the beddy centre if you can get hold of one the Auto cresta has the 3.5 gears only, it is a easy swap even to line up the gears is no problem with a bit of grease on the teeth. For a 179 or 186 I have a mate that has a 3.7 diff this is dead right for this size motor. If you are lucky enough to pick up a trimatic 3 speed with overdrive on it as I did the standard 4.2 (or what ever it is) Bedford diff is just right.
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Mezz
I have a 186 with a 3speed trimatic and I installed a hz diff with a ration of 3.5. I had the diff in before I converted to auto. Installing the auto added about an extra 300 rpm at 100 klm,at present at 100 klm revs are 3100 rpm. Still seems to be screeming too much for my liking
Joe
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Hi Joe what size tyres do you have & what is the overall diameter cheers Reid
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Reid, good question, never gave the tyre size a thought but must play a big part, glad to see someone is with it. I run 15s on back and now that I think of it it did make a big differance. :D
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Installing the auto added about an extra 300 rpm at 100 klm
hey joe.. the final drive on both gearboxes are the same ratio so it should not have altered your revs at 100km.. only thing i can think of is that the speedo gear ratio is different and your tacho reads differently.. is this possible? cause different final drive is same for both trimatic and 3 speed.
ben
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Been a few year since I put a tacho on
but they are electronic and work off the motor nothing to do with speedo drive ??? ??? ???
Plus there is this
http://www.sciforums.com/Manual-Transmission-power-loss-vs-Auto-t-43079.html (http://www.sciforums.com/Manual-Transmission-power-loss-vs-Auto-t-43079.html)
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Been a few year since I put a tacho on
but they are electronic and work off the motor nothing to do with speedo drive Huh Huh Huh
oh yeh duh!! that was really silly..
anyway the article explians that autos suck more power than manuals.. but how does that effect your engine revs at 100 clicks?
my van still does 3000 revs at 100 after ive done 200,000 + kms on the motor.. fair bit more tired and loss of power but still same amount of revs as when i first got her..
ben
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anyway the article explians that autos suck more power than manuals.. but how does that effect your engine revs at 100 clicks?
means more power required to drive auto, more power = more revs
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gday mezzmo i run a 3.08 banjo diff in mine with a 202 and trimatic. it takes off fine and cruises at 100 at around 2600-2700. i read on here u can put a hq-hz ute diff in but youll have to change the diff and shock mounts... not too big a job. take it easy... luke
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Running 14inch tyres with an overall diameter of 63 cm approx
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im no expert dont get me wrong but if the auto is doing more revs at 100 than the manual then wouldnt that mean the clutch is slipping?
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there is no external clutch with auto gear box only internal clutch bands inside auto gear box, my gear box is a new rebuild, there is always a revs differential between manual and auto boxs unless you get a lockable torque converter
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doesnt make sense to me and it didnt change my revs in my van between the 4 speed aussie box i had in and the trimatic i put in about 4 months ago. quite possible your speedo drive gear on your trimatic is different to the one on the 3 speed. so your speed is actually different therefore changing the revs.
ben
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Hi Joe my campa has 202 trimatic 3.7 diff 195 tyres on standard 14 inch rims & the tyres have an overall diameter of 650 cm & is reving its ring out at 100 ks will test it out when I get it back on the road Cheers Reid
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how well will a 186 go with a m21 and a 3.5:1 diff?
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yeh will be reving a bit able but not too much.. maybe 3grand at 100 or something around that.. put a celica box behind yours with the overdrive and it would be perfect!! not worth that much.. i picked up a conversion kit and box for $150
ben
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doesnt make sense to me and it didnt change my revs in my van between the 4 speed aussie box i had in and the trimatic i put in about 4 months ago.
The final drive gear ratios for the trimatic and the m21 4 speed are exactly the same.
Revs in top gear with a Trimatic fitted will be the same as the revs in top gear with an m21 4 speed box fitted.
Another way of saying this would be that the gear ratio of 3rd gear in a trimatic gearbox is the same as the
gear ratio of 4th gear in a m21 4 speed gearbox.
Jock
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yeh will be reving a bit able but not too much.. maybe 3grand at 100 or something around that.. put a celica box behind yours with the overdrive and it would be perfect!! not worth that much.. i picked up a conversion kit and box for $150
ben
will the celica box fit straight in with no diff mods? is that a supra 5 speed??? (not up with all the names...)
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toyota celica gearbox and toyota supra are different. the supras are quite a bit stronger. they put them behind v8s quite oftern.
celicas are plenty strong enough for the holden 6's
you wont need to modify your diff. but you will need to get your tailshaft modifyed.. and if you dont have a friend that can do it cheap you could end up spending more on the tail shaft mod than to buy the gearbox... ask morgan!! $300 later!!
oh and speedo cable.. last one i got custom made cost me $133 but that was just a bloke out of the paper..
ben
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might just stick with the m21..... ill put up with the high revs if it means cheap parts and plug and play.
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Hi Everyone, We are the proud owners of ex Niel Appleby- Lyndon CF van and are experiencing some difficulties in doing more than 150ks out of Port Pirie!!
First attempt t go t Adelaide 2 weeks ago was, was terminated at the 100 k mark (back home; get new power steering idler made) and away we go! $300 thankyou!!
Nah!Off we go last weekend, just Adelaide side of Port Wakefield; we have no drive happening!!
Towed back into Wakefield, Broken axle!!!
Now the problem appears t be getting a new (s/hand axle) From what the mechanic tells me is that I have light duty axles??????? I know from Niels thread I have a 3.5 diff ratio!1
Question????? does this mean I have a standard CF Highway diff??? What are my options; we need t get it going pronto; so we can make it to Geelong!!!!
Sorry about the essay; but we need some experienced "Guidence""
Cheers Brian & Carole ---------------------------------I'm still trying t ;D
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3.5 center diff I dont think is a standard beddy ratio. can you post a pick of the diff? count the splines on the end of the axles they should be a fine spline if its a borg warner center? If your in a hurry maybe your best bet would be chris ryan? what stud pattern are you running on the rear? if youv got a converted diff you should see the welds on the outside of the axles about 100-150 mill from the center out as below.
(http://i185.photobucket.com/albums/x234/craigc327/diffs081.jpg)
(http://i185.photobucket.com/albums/x234/craigc327/diffs082.jpg)
You may be able to find a good machine shop to make a new one but going that rout will cost you.
really lets see what diff you have.Im sure we can all put our heads together.
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Hi Craig, Thats the problem; the van is over a 100 ks away. To my knowledge there is no welds on the diff!! I think my best bet is t contact Niel Appleby as he should know whats in it!!
Cheers and thanks Brian :)
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geez if you were closer I would lend you one of mine, Im taking the salisbury diff out of the tow beddie and putting the 9" under, the salisbury comes with a holden stud pattern but is way too narrow for my liking
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taken from old site.
Hey guys. Ive decided to sell my van mostly because i just dont have the time anymore to get her the way i want her (work, bands and drinkin are getting in the way). I have had her for about 5 years but only driven for the last year but she has never let me down.
I was ganna just chuck it on ebay but figured i would post it here first. Im asking 3,000 but am negotiable and am located in beenleigh QLD.
email nsappleby@optusnet.com.au for questions or to get a contact number (i dont post phone numbers on public forums).
Any way heres the details.........
She is a 1978 SWB running a 93 VP commodore V6 and 4L60 (T700) 4 speed auto with QLD engineers certificate.
Back doors are welded up and the side door lifts up like a gull wing door (was like this when I bought it). CD player with 2 6x9's speakers in the back and one 6x9 speaker drivers side and one 5inch speaker pasenger side. inside is carpeted on floor and walls and roof (Roof is missing one pannel of carpet).
The diff is a borg warner 3.50:1 ratio (needs new pinon seal).
Front end was rebuilt a few years back with new ball joints, tie rods, control arm bushes etc.
has HQ front disks (not engineered), and new shockies on the front. I think the back ones need replacement as their is a bit of a knocking noise in the back end when hitting big bumps. She runs HQ stud pattern on the front and beddy on the back with 14x7 jelly bean mags with relitivly new 235/60 tyres (about 95% tread left).
I f@#ked up the pickup pipe and sender in the fuel tank. so from full to empty is only about 40ltres (cause it doesnt reach the other 20 ltres). Fuel consumption is getting me about 300 - 350 klms on around 40ltres of fuel (ive never run out of fuel just the most ive ever been able to get in it is about 43ltrs).
Body needs some attention, paint is a bit rough (I sprayed it my self and didnt do a very good job). A little bit of rust is starting to come through on the gutter channels and a few other places. I sanded back and treated most of the rust years ago but becasue i couldnt weld back then theres a little bit of bog through out.
She is currently registered but needs a tidy-up for a RWC so no RWC suplied. Personalised plates (Eropean plates Q 78 CF Z) will go with it.
Ive got a beddy manual and a Vp commodore manual that will go with it and ill chuck in a copy of a 4l60 rebuild manual as well as some front end parts and other odds and ends.
I think thats about all. Its sad cause ive had her for so long but its time for me to move on.
hope these photos work and photos of the engine can be found here..........
so she should be a borg warner your mechanic should know . so im thinking 31fine spline merlin?
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Thanks Craig, Will contact Niel, just to confirm what you have said.
All help greatly appreciated. There is a wrecked one here in Pirie, but don't know whats in it and whats for sale?? Will go see him tomorrow!!!
Cheers Brian ;D
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Diffs can be a nightmare! :o
More info and a few photos and we'll crack it for ya.
If you have a bedford stud pattern and a BW centre then there should be a weld somewhere along the axle housing.
There are two (?) ways of getting the axle into the diff.
-Some machine the axle to fit the BW planetary gears,
-some broach the gears to match the axle (means you can just slide the replacement axle in)
But if there's no weld and it's not a bedford stud pattern that's different.
so.......
What stud pattern?
Is there a weld anywhere between the centre and the brakes (both sides, all around)
Light duty axle is what? There's only one size in single wheel bedfords axles as far as i know - but i am often learning new things when it comes to bedford mutations (i assume heavy duty is a dually????)
I think beddys are 35mm dia from memory - don't quote me.
And i think i know a man in melb with wheel bearings if you need one
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Thanks Worzel for your coments!! As I said t Craig, the van is a 100 ks from here, so I am relying on whatever the Mechanic says!! If it was here; I'd be doing the job myself.
Here; I'd be doing a transplant-- We just need t get it back home for as cheap as possible!!
Will have serious talks with every Beddie owner at the Nats----------------if we get there????
Cheers Brian
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cool look fwd to meeting you and will help as much as possible. ;D ;D
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hey Worzel. I had an original beddie 'heavy duty' diff under the camper but unfortunatelty turfed it, it came with a larger diff housing and had 10" drums instead of the norm 8" drums on single wheel axles. I think I got that right coz it was about 4 years ago when I lifted it out and remember it being much heavier and bulkier then the standard size beddie diff, all the mounting brackets and such were original factory made, it was high speed from memory and I swapped it for a 9" then put it under the donor van and then sold the lot to somewhere in the Dandenongs
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At last some "good news", A very old gentleman here in Pirie has his own CF camper van and a wrecked Beddie in his backyard. He has given me a complete diff; so worst case cenario is t tro it in and hope it takes us t Beddie Heaven-----ie The Nats!!!
Cheers Brian--------- ::) is that a smile I see there??
P.S. Thanks for all the help and advice!!!!!
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Fingers and toes crossed for you Brian....I hope it all works well for ya.... ;D cheers...johnno
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good on you brian. ;D
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hey Worzel. I had an original beddie 'heavy duty' diff under the camper but unfortunatelty turfed it, it came with a larger diff housing and had 10" drums instead of the norm 8" drums on single wheel axles
well there ya go. Learning all the time
sounds like you'd be unlucky to have one cause parts would be a sh1t :-\
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just pulled apart my borg warner diff
and was well surprised?!
it has redrilled splines that fit hq stud pattern...with beddy wheel bearings ..n lockheed wheel cylinders n pads
nothing is ever standard on a beddy ???
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Hey Peoples< The Saga continues!!!! Got my new (second/diff) home t/day (walked it home on a sacktruck) Here we go again, the one in the van is a 21 spline and of course the one I got t/day is a 25 spline------ Major learning curve happening here!!!
Correct me if I'm wrong! G diff 8/37 ratio should be 25 spline axle??????
F diff 7/37 ratio should be 21 spline axle?????
So what I'm gonna do is thro the complete diff Rust and all, under the old girl (not Carole) t get her home!!!
If anyone has a 21 spline axle for sale, I could be interested, unless I go the Holden salisbury diff way!!
I am confused but "learning"
Cheers Brian O :-[