View Full Version : PRO GEARS vs STREET GEARS
59RAT
10-12-2008, 07:46 PM
They say not to run Pros on the street why? I broke a pinion today and think it might be time to up grade, the car gets a lot of street time tho. I didn't get the first pass in, broke at the line. Car's 4600 lbs. and about 1400/1500 hp. Any ideals or help? Thanks Rod
redcam622
10-12-2008, 07:53 PM
Pro gears are softer than street gears and wear out much quicker due to heat..they flex instead of break on cars that launch hard...i don't know how others feel about them,but i run street gears in every thing and have never had a problem..3400lbs and 7 second passes...just my 2 cents
Scott @ DLS
10-12-2008, 09:35 PM
Pro gears will take up to 3-4 miles of easy driving, I have driven mine to a few car shows without and extra wear issues. If your breaking teeth off of the pinion your gear was not set up properly. When you start breaking teeth off the ring gear then it's time to upgrade.
What axle are your running? A Dana 60 would be the best of all the axles if you have to stay with a street gear.
59RAT
10-13-2008, 07:13 AM
Thank you Gentlemen, I'm running a Moser built 9" with 35 spline axels. I snaped the pinion in half on the shaft. They didn't last all that long. I guess I'll try another set of street gears it may have just been a weak set. Rod
Uncle Paul
10-13-2008, 11:55 AM
A "Pro Gear" set is made of as different material (mostly 9310)and different heat treat then standard "Street Gears" (usually 8620). The heat generated by street use will cause them to wear out faster. If you broke a pinion I agree with Scott and I would check the wear pattern on the parts remaining and see if something else didn't cause the failure.
TOPLESS63
10-13-2008, 08:43 PM
you can soften a street gear a little by putting in oven a 450 for a hour and let cool. helped me when i used to run street gears with 8 3/4 rear end
59RAT
10-14-2008, 07:32 AM
Thanks , more info. is always good. I pulled the center out of the wagon last night. It's the same set up as the Impala, going the pull the one out of the Impala tonight and put this one back in. I will definitely check the parts out. Going to try and make it back to the track Sunday. That was not a cheap day last Sunday track rental 2 hours each way and no data. Rod
Hey Rod, Barrys ran a pro gear in his 3800lb Chevelle for years on the street with not one problem.:D
59RAT
10-14-2008, 02:46 PM
Hey Rod, Barrys ran a pro gear in his 3800lb Chevelle for years on the street with not one problem.:D
He has, does he put a lot of miles on the street? I'm talking like 100s at any one time? The reason I ask is I want to do Drag week at least once. I would have done it this year but the motor didn't get back in the car till 2 days before it. With what happen this weekend, it's probably a good thing I didn't make it. By the way that's an awesome BLOWER SUPPORT you've come up with. Rod
He has, does he put a lot of miles on the street? I'm talking like 100s at any one time? The reason I ask is I want to do Drag week at least once. I would have done it this year but the motor didn't get back in the car till 2 days before it. With what happen this weekend, it's probably a good thing I didn't make it. By the way that's an awesome BLOWER SUPPORT you've come up with. Rod
I wouldnt say hundreds at a time but maybe a hundred at a time. Been in there for 8 years I think and countless passes. Carefull attention to break in I think has helped.
Thanks Rod!, you get it on? Shoot me some pics if you get a chance. I'll add them to my site.
Barry
10-14-2008, 10:35 PM
I wouldnt say hundreds at a time but maybe a hundred at a time. Been in there for 8 years I think and countless passes. Carefull attention to break in I think has helped.
Damn Jake........I didn't think you remembered me........:p
Jake is mostly right on this topic. I did run a 4:11 Pro Gear for many years of abuse on the street and at the track. Not alot of "highway miles" but alot of miles just cruising around town with no issues. If they're set up right and you're easy on them around turns, you should be ok.
For the last couple years I've ran a 3:73 street gear since I couldn't find that ratio in a pro gear for my 12 bolt. Also, no issues so far from track abuse.
Like Jake said in the above, I always warm up the rear end before making any passes which I believe only helps the gears take the abuse.
Damn Jake........I didn't think you remembered me........:p
Jake is mostly right on this topic. I did run a 4:11 Pro Gear for many years of abuse on the street and at the track. Not alot of "highway miles" but alot of miles just cruising around town with no issues. If they're set up right and you're easy on them around turns, you should be ok.
For the last couple years I've ran a 3:73 street gear since I couldn't find that ratio in a pro gear for my 12 bolt. Also, no issues so far from track abuse.
Like Jake said in the above, I always warm up the rear end before making any passes which I believe only helps the gears take the abuse.
How could I forget you.:p Now lets get some headers built!:p
59RAT
10-16-2008, 12:54 PM
I just thought I would share.http://i220.photobucket.com/albums/dd54/59rat/IMPALAREAR004.jpg
http://i220.photobucket.com/albums/dd54/59rat/IMPALAREAR003.jpg
http://i220.photobucket.com/albums/dd54/59rat/IMPALAREAR002.jpg
http://i220.photobucket.com/albums/dd54/59rat/IMPALAREAR001.jpg
...
Scott @ DLS
10-16-2008, 03:26 PM
WOW, I would say it's time for a 35 spline pro gear.
Run to Rund
10-17-2008, 11:56 PM
Looks like its time for the 35 spline pinion. That means Pro gears too, as the 35 spline pinions aren't made in 8620 steel.
59RAT
10-18-2008, 07:48 AM
I have not looked hard yet but, who makes a pro gear in 3:70s?
Scott @ DLS
10-19-2008, 01:02 AM
Strange, Motive Performance and Richmond make 35 spline pinion gears for that. You will have to change the support and pinion yoke to accomodate.
sc68z28
10-28-2008, 12:12 AM
Rod, my 9" Motive streetgear pinion broke in the same place.
35 spline Pro Gear now, with just a little street driving.
---Bill.
http://i12.photobucket.com/albums/a224/sc68z28/5-7-06002.jpg
SHAKEY
10-28-2008, 10:03 AM
i did the same thing!! 3.70 strange street gear.. 1st pass at the track?? snapped pinion right behind the yoke!!! sucked!!! up graded to the 3.60 pro gear!! no problems yet!!
59RAT
10-28-2008, 02:02 PM
Thanks for the info. This seems to be the way I learn all my lessons, (the hard way). LOL Well I went back to the track Sunday (last week) and broke the other locker that goes in the wagon. I now know that a locker will not hold the HP & weight together. It snapped the splines inside the locker itself. I can get the parts to rebuild the locker but it will go on the shelf as a spare for the wagon (a lot less hp and 1200lbs. lighter). I went to a 40 spline spool and axles with a 370 35 spline pro gear. Had a hard time finding anyone with the 370 pros in stock. I'm putting it in the car tonight and try it this weekend once again. Let's see what breaks this time. LOL Rod
Horndog
10-28-2008, 02:33 PM
Thanks for the info. This seems to be the way I learn all my lessons, (the hard way). LOL Well I went back to the track Sunday (last week) and broke the other locker that goes in the wagon. I now know that a locker will not hold the HP & weight together. It snapped the splines inside the locker itself. I can get the parts to rebuild the locker but it will go on the shelf as a spare for the wagon (a lot less hp and 1200lbs. lighter). I went to a 40 spline spool and axles with a 370 35 spline pro gear. Had a hard time finding anyone with the 370 pros in stock. I'm putting it in the car tonight and try it this weekend once again. Let's see what breaks this time. LOL Rod
FWIW - a buddy broke the pinion gear in his rear end on the launch, fixed it and the next time out the trans took a dive. No low gear - the trans is a built C-4 behind a stroked 460 Ford in a fox body.
I've always heard that if the rear end breaks under high load, get the trans apart and look at it.
dougd
10-29-2008, 05:40 PM
There are small pinion pro gear from Richmond that is heat treated for wear .You get the best of both worlds , soft core for flex and a good heat treat for lots of street miles, we have had these for years and have had customers use these at Bonneville and very high powered street cars without any failures.We have 3.00 , 3.07 , 3.10 ,3.15 , 3.25, 3.70, 3.80, 3.89 , 4.11, 4.22, 4.29, 4.33, 4.75, 5.50 , 5.67 , 6.40 .We can also lighten these if needed.
sc68z28
10-29-2008, 10:37 PM
There are small pinion pro gear from Richmond that is heat treated for wear .
Who is doing the heat treat, Richmond?
Why only small pinion?
You say "Pro gear from Richmond" and you list ratios that don't come in a Pro gear, IE, 3.00, 3.07, 3.10.... :confused: Or do they?
---Bill.
dougd
10-29-2008, 10:57 PM
Richmong does the additional heat treat on them for better life.We dont have enough call on the big pinion gears to have the extra heat treat done to them.These ratios are richmond 9310's and i have all these on the shelf except the 4.44 which will be back on the shelf in less than a week, Nascar also uses a gear like these, but they come rem finished and cut for a internal oil pump drive.I also have the big pinion in 3.40 , 3.50 , 4.11 , 4.29, 4.57 , 4.86 , also in 9310's.
THE STING
11-01-2008, 02:24 PM
At 4600lbs i doubt anything will last, i'm assuming you use a transbrake....footbrake it . if its lazy because of the turbo, hit it with Nos for the first 150ft....
I would put an alum pinion support in also, they help with shock of the launch.
59RAT
11-07-2008, 02:11 PM
At 4600lbs i doubt anything will last, i'm assuming you use a transbrake....footbrake it . if its lazy because of the turbo, hit it with Nos for the first 150ft....
I was foot braking both times. This past weekend I got some data. It was hooking good the first few feet then go up in smoke. I started pulling timing on the hit and started using the trans brake. It was working better but now I have some other problems (tune up). I never got a full pass. Rod
Brad, I did get an alum. support. Thanks Rod
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