[PunchT37]

Originally Posted by slowbird

Good info, thanks.
We currently have 4.11's and im working on making the car more street friendly for my dad. I know comverter plays a roll but im just not sure how much one slips going down the road at a steady pace.

Every now and then, it turns 2800 or so. So, wind, da, inclines will affect the converter slip.

[Ponchy]

Originally Posted by Half-Inch Stud

Drove the GTO today ( was 58 degrees); Overdrive uphill at 30 mph was just fine. was bumping 3rd-4th, 4th-3rd just to see what RPM was; 2100 to 1900 and no lugging.

Camed 236-244 9.0:1 as signed below.

Becareful doing that.
A friend's then-girlfriend did that with a Toyota Celica and grenaded the transmission because she was driving in 5th at 30-35 all the time.
You've got to have enough "gear speed" inside the tranny to get good oil flow (since its the gears that throw the oil around and lubricate everything).
Too high gear at too slow speed will kill a manual tranny every time.

[geeteeohguy]

Originally Posted by Ponchy

Becareful doing that.
A friend's then-girlfriend did that with a Toyota Celica and grenaded the transmission because she was driving in 5th at 30-35 all the time.
You've got to have enough "gear speed" inside the tranny to get good oil flow (since its the gears that throw the oil around and lubricate everything).
Too high gear at too slow speed will kill a manual tranny every time.

This was a very common problem on early 1980's Toyotas (and other Japanese cars) with the 5 speed. People then were not used to 5 speeds and would lug the engine/trans and lose 5th gear. The original owner did it with my '83 Toyota pickup. Had the trans rebuilt and drove it properly after that. I only use 5th at 70 mph or more with the 31's it runs on. Slowbird said his rpm now at 70 is 2700-2800 rpm.....Funny, that's what my '65 GTO turns with 29" tall tires (2.5" taller than stock) and a 3.36 rear gear. So Slowbird must be running very tall tires IMO to be turning that low of an rpm with 3.55's. He should be about 3200 with stock tires, so sum-sing-wong.

[slowbird]

Originally Posted by geeteeohguy

This was a very common problem on early 1980's Toyotas (and other Japanese cars) with the 5 speed. People then were not used to 5 speeds and would lug the engine/trans and lose 5th gear. The original owner did it with my '83 Toyota pickup. Had the trans rebuilt and drove it properly after that. I only use 5th at 70 mph or more with the 31's it runs on. Slowbird said his rpm now at 70 is 2700-2800 rpm.....Funny, that's what my '65 GTO turns with 29" tall tires (2.5" taller than stock) and a 3.36 rear gear. So Slowbird must be running very tall tires IMO to be turning that low of an rpm with 3.55's. He should be about 3200 with stock tires, so sum-sing-wong.

Yes we have tall tires, got them to tame down the 4.11 on the street.

[Ponchy]

Originally Posted by geeteeohguy

This was a very common problem on early 1980's Toyotas (and other Japanese cars) with the 5 speed. People then were not used to 5 speeds and would lug the engine/trans and lose 5th gear. The original owner did it with my '83 Toyota pickup. Had the trans rebuilt and drove it properly after that. I only use 5th at 70 mph or more with the 31's it runs on. Slowbird said his rpm now at 70 is 2700-2800 rpm.....Funny, that's what my '65 GTO turns with 29" tall tires (2.5" taller than stock) and a 3.36 rear gear. So Slowbird must be running very tall tires IMO to be turning that low of an rpm with 3.55's. He should be about 3200 with stock tires, so sum-sing-wong.

Actually, it was a silver '75 GT, but same result.
We actually tried to pull that tranny apart and fix it....after removing C-clip number 5,135,719,654 and not really being much farther along than when we started, we bagged the idea of repair and just got another one.
The girlfriend was then "instructed" not to use 5th unless going AT LEAST 50 mph.
The owners manual for my ol' Mazda truck said to never use 5th below 45 mph (and now you can say you actually know someone who read their owner's manual).
I adhered to that doctrine for the next 21 years, until it blew a head gasket (and possibly cracked the head, too), and decided I was tired of working on it.

Ponchy

[The Champ]

Originally Posted by geeteeohguy

Funny, that's what my '65 GTO turns with 29" tall tires (2.5" taller than stock) and a 3.36 rear gear.

FWIW - the 7.75x14's that came stock on a '65 GTO were 27" tall, not 26.5" tall.

[Will]

Originally Posted by geeteeohguy

This was a very common problem on early 1980's Toyotas (and other Japanese cars) with the 5 speed. People then were not used to 5 speeds and would lug the engine/trans and lose 5th gear. The original owner did it with my '83 Toyota pickup. Had the trans rebuilt and drove it properly after that. I only use 5th at 70 mph or more with the 31's it runs on...

Serious thread drift alert...

Love those old 'yotas. Here's my '84 from this last spring. Only has 158k on the clock.

5th gear is getting noisy. I only ever use it on the freeway. The G52 trannies aren't all that strong though. I have a modified/beefed up W56 waiting for me to find the time to install it.

Okay, back to the Pontiyaks!

[Ponchy]

Originally Posted by Will

Serious thread drift alert...Okay, back to the Pontiyaks!

That one's on me. Apologies.
Only meant to make a point about driving too slow in too high a gear.
...back on subject...

[Formulajones]

I've never had that be a problem in the bigger GM transmissions like the T56 or the TKO 5 speeds. I've driven those for decades in overdrive at 35 mph and have never had an issue with lube or failures in any of those transmissions. I wouldn't even worry about it.

[Ponchy]

As long as there's enough oil flow to keep everything properly lubricated, then it wouldn't be a problem.
Can only speak from experience, though and those were my experiences.
Does seem like kind of a low speed to use an overdrive gear.....of course, if yours aren't, that might be one reason why.

[Formulajones]

The one we currently daily drive has 3.55's with a .64 5th gear. We've cruised around daily through town in 5th gear at 35-ish mph for the last 4-5 years with it. The car is driven everywhere. Never an issue.

Treated all the T56 cars we had previously the same way for decades.

I think the examples you guys are talking about are little foreign car transmissions, completely different deal.

[i82much]

real hot rods have solid lifters and 4.88’s, buzz your head off at 45 mph and won’t idle below 1500 rpm. what a bunch of sissies! you guys probably have air conditioning and power brakes too, dontcha?

(sneaks off py forum to go look at gear vendors and vintage air web pages ...)

[Sirrotica]

Originally Posted by Ponchy

Becareful doing that.
A friend's then-girlfriend did that with a Toyota Celica and grenaded the transmission because she was driving in 5th at 30-35 all the time.
You've got to have enough "gear speed" inside the tranny to get good oil flow (since its the gears that throw the oil around and lubricate everything).
Too high gear at too slow speed will kill a manual tranny every time.

FWIW, Mark (HIS) has a full manually shifted 4L80E in his 68 GTO, I don't think he has to worry about lugging it, and ruining his transmission..........

Link to his install of the 4L80E in his GTO:

http://forums.maxperformanceinc.com/...d.php?t=823023

Also documented that there is no major sheet metal surgery to install a 4L80E in an A body too, contrary to rumors that are circulated on PY. On some cars a few bumps with a hammer is all that is needed, some cars need no clearancing. Mark documented he needed no tunnel clearancing when doing his swap on his 68 GTO.

[Formulajones]

Originally Posted by i82much

real hot rods have solid lifters and 4.88’s, buzz your head off at 45 mph and won’t idle below 1500 rpm. what a bunch of sissies! you guys probably have air conditioning and power brakes too, dontcha?

(sneaks off py forum to go look at gear vendors and vintage air web pages ...)

......

[Formulajones]

Originally Posted by Sirrotica

Also documented that there is no major sheet metal surgery to install a 4L80E in an A body too, contrary to rumors that are circulated on PY. On some cars a few bumps with a hammer is all that is needed, some cars need no clearancing.

I'm not even sure how that stuff gets started. I've told people that for a long time here but.........

Just ordered a 4L80E for another Abody swap coming soon

[Sirrotica]

Originally Posted by Formulajones

I'm not even sure how that stuff gets started. I've told people that for a long time here but.........

Just ordered a 4L80E for another Abody swap coming soon

It's usually the 200r4 proponents that try to scare people from using a 4L80E, if you go back and look at all the posts. Not only has it been documented by Half Inch Stud (Mark) on PY, Hot Rod magazine has been more than a few articles documenting the 4L80E swaps into about every chevy muscle car (which are the same as our Pontiacs underneath) that there are no major tunnel mods needed, most times there are no mods needed. If the later core is used (97 and later) the rear cooling line area may need a bump with a hammer to gain some clearance. Mark used an 91-96 core, and had plenty of clearance.

For some strange reason GM cast ears onto the bell housing area on the 4L80E cases used in the truck applications. It may be for the machinery used to build the transmissions at the factory, not sure why they're are there. Those should be trimmed off also before lifting the transmission up into the tunnel for clearancing. No one has ever came out with a reason they're there in the first place, so trimming them off just makes sense to simplify the install.

[b-man]

One of the better gear ratio/tire height/mph calculators.

https://weddleindustries.com/gear-calculator

[Ponchy]

Originally Posted by b-man

One of the better gear ratio/tire height/mph calculators.

https://weddleindustries.com/gear-calculator

That's a pretty cool calculator.
I like how it gives you a lot of info with just a little input.

As for me, I know the formula, so all I need is a pocket calculator.

speed (mph) x effective gear ratio x 336 / tire height (inches)

The result is engine rpm for a given road speed.

Run it forwards and backwards. It works.
You can have a lot of fun "bench racing" using that formula.

[unruhjonny]

I realize the original intent of this discussion is resolved, but I wanted to chime in.
When I daily drove my Firebird (3.55:1), I would just cruise at a speed (on the highway) that I felt comfortable at;
If the limit was too high for my liking, I'd just slide over to the right (slow) lane, and if I was concerned about being too slow for the flow of traffic, I'd speed up for a bit, and take a turn off to get onto a secondary highway instead of staying on a major one and being at a speed I didn't care for.

Never once did I consider going with less gear.

[Formulajones]

Originally Posted by unruhjonny

I realize the original intent of this discussion is resolved, but I wanted to chime in.
When I daily drove my Firebird (3.55:1), I would just cruise at a speed (on the highway) that I felt comfortable at;
If the limit was too high for my liking, I'd just slide over to the right (slow) lane, and if I was concerned about being too slow for the flow of traffic, I'd speed up for a bit, and take a turn off to get onto a secondary highway instead of staying on a major one and being at a speed I didn't care for.

Never once did I consider going with less gear.

That's pretty much how I feel. I've done cross country trips with 3.73's, with a 28" tire it wasn't horrible. 65 was doable. Just takes a little extra time to get where you're going.

For the first 4 years of daily driving the Z I had 3.55's in it with a 27" tire and an M-20 muncie. It was fine, 65 was comfortable and we did a lot of long trips with it that way. The bird has 3.31's and I still use it as my main transportation everywhere, with some long trips mixed in. Doesn't bother me.

Most of the time I'm on secondary roads anyway, seldom will I take the highway unless it's necessary. I don't like the highway even if I'm in a car that goes faster, just don't care for it. That's where all the idiots are.