Home » Public Forums » GMCnet » West coast trip, will a 3.07 final drive be OK? not towing
| West coast trip, will a 3.07 final drive be OK? not towing [message #330024] |
Thu, 15 March 2018 16:09  |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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So we are thinking of doing a trip to the west coast in our '77 pb. The engine was rebuilt in 2010 by Dick Patterson and I have a Rochester TBI with the EBL system and spark control. The transmission was replaced at the same time with a rebuilt through DickP as well.
I'm wondering if I need to worry about changing the final drive from the OEM 3.07 to a 3.55 or 3.70. We are not towing anything.
Thoughts?
Thanks
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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| Re: West coast trip, will a 3.07 final drive be OK? not towing [message #330025 is a reply to message #330024] |
Thu, 15 March 2018 16:27  |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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You will have no problems with the 3.07. I drove mine about 8000 miles all around the Southwest with the stock final drive before upgrading to a 3.70. Either way, you will probably need to downshift to pull some of the grades. I usually pull it down into 'super' at around 40 MPH and shift back to drive at about 50.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: [GMCnet] West coast trip, will a 3.07 final drive be OK? not towing [message #330027 is a reply to message #330024] |
Thu, 15 March 2018 16:36 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Bruce, which route are you taking? North like Interstate 80 or 90, or
South like 40? Some differences in passes and gradients exist. I have run
both ways, once with stock gearing and once with 3:70 and a 403. Both did
well. The big difference you will notice is downshift points. The stock
gearing will downshift sooner than the 3:55 will on the same grade. But,
you have more torque and horsepower than stock, so that changes the
equation a good bit. On similarly equipped coaches to yours, that I have
experience with, they don't downshift at all, and still run 10 inches of
vacuum on the steepest grades. On my 403, when my vacuum falls off below
that point, I manually downshift to avoid going into the secondaries on the
carb. My Royale is a heavy coach, and sometimes I pull a trailer full of
stuff.
Jim Hupy
On Mar 15, 2018 2:10 PM, "Bruce Hislop" wrote:
> So we are thinking of doing a trip to the west coast in our '77 pb. The
> engine was rebuilt in 2010 by Dick Patterson and I have a Rochester TBI with
> the EBL system and spark control. The transmission was replaced at the
> same time with a rebuilt through DickP as well.
>
> I'm wondering if I need to worry about changing the final drive from the
> OEM 3.07 to a 3.55 or 3.70. We are not towing anything.
>
> Thoughts?
>
> Thanks
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: West coast trip, will a 3.07 final drive be OK? not towing [message #330028 is a reply to message #330024] |
Thu, 15 March 2018 17:10 |
Scott Nutter
Messages: 782
Registered: January 2015
Location: Houston/San Diego
Karma: 4
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Senior Member |
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Bruce,
Drive it out as a 3.07. If on the way you have any grade issues, take it to Applied in the Bay Area and have him put a final drive of your choice in.
While he is doing that, rent a car and check out the wine country! Beautiful country and a great time of the year to go.
Enjoy!
Scott.
Scott Nutter
1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI
Houston, Texas
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| Re: [GMCnet] West coast trip, will a 3.07 final drive be OK? not towing [message #330030 is a reply to message #330028] |
Thu, 15 March 2018 17:53 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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There is no need to put in a lower gear ratio, but from what we have seen
since 1990 is that the transmission hold up better.
The gas milage does not differ.
We have sold over 3,000 units, so we receive feedback.
Things like new fuel lines,fan clutch, and New fuel filters. must be done.
On Thu, Mar 15, 2018 at 3:10 PM, Scott Nutter wrote:
> Bruce,
> Drive it out as a 3.07. If on the way you have any grade issues, take it
> to Applied in the Bay Area and have him put a final drive of your choice in.
> While he is doing that, rent a car and check out the wine country!
> Beautiful country and a great time of the year to go.
> Enjoy!
> Scott.
> --
> Scott Nutter
> 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final
> drive, Quad bags, tankless water heater, everything Lenzi.
> Houston, Texas
>
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: West coast trip, will a 3.07 final drive be OK? not towing [message #330032 is a reply to message #330024] |
Thu, 15 March 2018 18:33 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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No, use the gears to go up the hill and down the hill. Use the brakes to limit engine speeds only. If you are worried about downshifting then pull the hill in S and leave it there for the way down. I have done long grades with 3.07 and now have 3.42. Less need to use S as much and seems happier
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: [GMCnet] West coast trip, will a 3.07 final drive be OK? not towing [message #330034 is a reply to message #330029] |
Thu, 15 March 2018 19:14 |
Emery Stora
Messages: 959
Registered: January 2011
Karma: 4
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I don’t agree. I used a 3.07 for about 30 years before buying my 3.55 and I downshifted it for downhills all the time.
Emery Stora
77 Kingsley
Frederick, CO
> On Mar 15, 2018, at 4:42 PM, Gary Worobec wrote:
>
> Apparently these transmissions to not like a downhill downshift. So cresting the top of the hill in drive it is better to leave it in drive and use the brakes instead of dropping down into a lower gear. This is what i have heard.
>
>> On Mar 15, 2018, at 2:09 PM, Bruce Hislop wrote:
>>
>> So we are thinking of doing a trip to the west coast in our '77 pb. The engine was rebuilt in 2010 by Dick Patterson and I have a Rochester TBI with
>> the EBL system and spark control. The transmission was replaced at the same time with a rebuilt through DickP as well.
>>
>> I'm wondering if I need to worry about changing the final drive from the OEM 3.07 to a 3.55 or 3.70. We are not towing anything.
>>
>> Thoughts?
>>
>> Thanks
>>
>> --
>> Bruce Hislop
>> ON Canada
>> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
>> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
>> My Staff says I never listen to them, or something like that
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> Gary Worobec
> gtw5@earthlink.net
> 1973 23 GMC Glacier
> 1935 Dodge pickup
>
>
>
>
>
>
> _______________________________________________
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| Re: [GMCnet] West coast trip, will a 3.07 final drive be OK? not towing [message #330035 is a reply to message #330034] |
Thu, 15 March 2018 19:19 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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I am not sure using the transmission as a grade retard will have much of an
effect on longevity. I have always used mine that way, much more so before
I changed to 3:70 final drive gears. But, I only have 100 thousand miles on
this one.
Jim Hupy
On Mar 15, 2018 5:15 PM, "Emery Stora" wrote:
> I don’t agree. I used a 3.07 for about 30 years before buying my 3.55 and
> I downshifted it for downhills all the time.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On Mar 15, 2018, at 4:42 PM, Gary Worobec wrote:
>>
>> Apparently these transmissions to not like a downhill downshift. So
> cresting the top of the hill in drive it is better to leave it in drive and
> use the brakes instead of dropping down into a lower gear. This is what i
> have heard.
>>
>>> On Mar 15, 2018, at 2:09 PM, Bruce Hislop wrote:
>>>
>>> So we are thinking of doing a trip to the west coast in our '77 pb.
> The engine was rebuilt in 2010 by Dick Patterson and I have a Rochester TBI
> with
>>> the EBL system and spark control. The transmission was replaced at the
> same time with a rebuilt through DickP as well.
>>>
>>> I'm wondering if I need to worry about changing the final drive from
> the OEM 3.07 to a 3.55 or 3.70. We are not towing anything.
>>>
>>> Thoughts?
>>>
>>> Thanks
>>>
>>> --
>>> Bruce Hislop
>>> ON Canada
>>> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
>>> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
>>> My Staff says I never listen to them, or something like that
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>> Gary Worobec
>> gtw5@earthlink.net
>> 1973 23 GMC Glacier
>> 1935 Dodge pickup
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> GMCnet mailing list
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>
>
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| Re: West coast trip, will a 3.07 final drive be OK? not towing [message #330042 is a reply to message #330024] |
Thu, 15 March 2018 20:40 |
JohnS
Messages: 126
Registered: December 2014
Location: Vacaville, CA
Karma: -2
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We have driven all over the West Coast & Rockies with a stock final drive. About 280000 miles on the 77 Eleganza before putting in a Manny Power Drive chain when he did a precautionary transmission rebuild. You may spend a little more time in 2nd gear in the mountains. My rule of thumb is to manually shift down before 45mph (do not wait for it to shift itself). Do the same thing on steep downgrades, shift in to 2nd before it gets above 45, just don't wait to pull it down when you are going downhill fast. You may not be the first to the top or the bottom, but you should still will be running OK when you get back to the Flatlands. Just What We Did.
John Shutzbaugh, Vacaville, CA, ncserv@aol.com;
78 Buskirk stretch, "What were we thinking?"
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| Re: [GMCnet] West coast trip, will a 3.07 final drive be OK? not towing [message #330047 is a reply to message #330042] |
Thu, 15 March 2018 21:00 |
Gary Worobec
Messages: 867
Registered: May 2005
Karma: -1
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Agreed, pulling it down a gear while going downhill is an issue according to Manny.
> On Mar 15, 2018, at 6:40 PM, John Shutzbaugh wrote:
>
> We have driven all over the West Coast & Rockies with a stock final drive. About 280000 miles on the 77 Eleganza before putting in a Manny Power
> Drive chain when he did a precautionary transmission rebuild. You may spend a little more time in 2nd gear in the mountains. My rule of thumb is to
> manually shift down before 45mph (do not wait for it to shift itself). Do the same thing on steep downgrades, shift in to 2nd before it gets above
> 45, just don't wait to pull it down when you are going downhill fast. You may not be the first to the top or the bottom, but you should still will be
> running OK when you get back to the Flatlands. Just What We Did.
> --
> John Shutzbaugh, Vacaville, CA, ncserv@aol.com;
> 77 Eleganza, bought it new, can't blame PO, and
> 78 Buskirk stretch, "What were we thinking?"
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Gary Worobec
gtw5@earthlink.net
1973 23 GMC Glacier
1935 Dodge pickup
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| [GMCnet] rRe: West coast trip, will a 3.07 final drive be OK? not towing [message #330048 is a reply to message #330024] |
Thu, 15 March 2018 21:34 |
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Anonymous
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Bruce
I have driven across the country towing a car and on another trip a trailer using what i assume is the stock gearing. You need to use the shifter to keep the revs up on the climbs also helps on the down grades as well . That was ontario to bc . One trip was in the winter don't ask.
On Thursday, March 15, 2018, 2:10:42 PM PDT, Bruce Hislop wrote:
So we are thinking of doing a trip to the west coast in our '77 pb. The engine was rebuilt in 2010 by Dick Patterson and I have a Rochester TBI with
the EBL system and spark control. The transmission was replaced at the same time with a rebuilt through DickP as well.
I'm wondering if I need to worry about changing the final drive from the OEM 3.07 to a 3.55 or 3.70. We are not towing anything.
Thoughts?
Thanks
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
_______________________________________________
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Unsubscribe or Change List Options:
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| Re: [GMCnet] West coast trip, will a 3.07 final drive be OK? not towing [message #330084 is a reply to message #330047] |
Fri, 16 March 2018 18:40 |
Ronald Pottol
Messages: 505
Registered: September 2012
Location: Redwood City, California
Karma: -2
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Senior Member |
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The list has been over this, don't just pop it into s at high speed, but
slow to a reasonable point, shift to s, and then let it coast back to to
the speed it holds it at.
Or so I remember. I sur wouldn't use stock brakes to control my speed all
the way down our big grades.
On Thu, Mar 15, 2018, 19:01 Gary Worobec wrote:
> Agreed, pulling it down a gear while going downhill is an issue according
> to Manny.
>
>> On Mar 15, 2018, at 6:40 PM, John Shutzbaugh
> wrote:
>>
>> We have driven all over the West Coast & Rockies with a stock final
> drive. About 280000 miles on the 77 Eleganza before putting in a Manny
> Power
>> Drive chain when he did a precautionary transmission rebuild. You may
> spend a little more time in 2nd gear in the mountains. My rule of thumb is
> to
>> manually shift down before 45mph (do not wait for it to shift itself).
> Do the same thing on steep downgrades, shift in to 2nd before it gets above
>> 45, just don't wait to pull it down when you are going downhill fast.
> You may not be the first to the top or the bottom, but you should still
> will be
>> running OK when you get back to the Flatlands. Just What We Did.
>> --
>> John Shutzbaugh, Vacaville, CA, ncserv@aol.com;
>> 77 Eleganza, bought it new, can't blame PO, and
>> 78 Buskirk stretch, "What were we thinking?"
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> Gary Worobec
> gtw5@earthlink.net
> 1973 23 GMC Glacier
> 1935 Dodge pickup
>
>
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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1973 26' GM outfitted
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