Every transmission builder I ever met strives to build 100% of your work with no come back's. With some parts being inspected & reused, installs done by somebody else. Stuff that goes wrong on a vehicle. Some things you just cannot control, no matter what you do.
If you have built 100 units and only 2 comeback for rework, that would be a 2% CB ratio.
Personally I have about a 4% ratio, out of the last 100 builds I've had 4 comebacks. 2 young kids that stacked a pump and broke a pump rotor. 1 was a blown rear planet set and the other was P1810 code for a bad PSM.
What do you feel is an acceptable % of comebacks?

 

If you have a 96% success rate, I'd say that's pretty good, especially if you're throwing in the variable of customers doing their own installation.

We all strive for excellence, and this board is a shining example of that. That's why I come here every day. The sharpest guys are here, who emphasize testing/ measuring things instead of just throwing money/ parts at perceived issues.

Hell, I never thought about vacuum testing before I frequented this board. I'd heard of it, but I didn't think about how it could effect transmission operation. I figured that throwing new clutches and seals at a burned up transmission could make it like new, but as I'm sure we both know, THAT ISN'T SO.

The point I'm trying to make is that you eliminate every variable on YOUR end (vacuum test valve body, air check clutch packs, ensure that all clearances are within specifications), there is little room for error except for the installer.

 

I didn't vacuum test until about 5 years ago. I wanted to, I just could turn loose of $500 for a Sonnax vacuum test set up. I saw Maroonmonsterls1's post on building a Vac test stand and I couldn't order the fitting's fast enough. Been testing ever since.
I also made a Air test plate that allows me to air test all apply functions & the 3rd release of the band. Knowing that it air tests after full assembly with 40 PSI is a great comfort. I vac test the valve body and make adjustments, then air test all the valves for movement with a separate Sonnax air test plate.
Yeas it's time consuming, but makes a better job overall.

 

96% sounds pretty dang good to me, although I’m not sure what the industry standard is. To keep rework low, and on the idea of honoring warranties (providing that the unit is installed correctly) how are you guys verifying that the customer installed everything correctly like converter and flexplate fitment, use of a trans cooler, correct fittings, calibrating the dipstick tube, etc? You would think that providing instruction of all this along with the sale of the transmission would be good enough, but still mistakes happen. Some guys I talked to said that they require a video of these things being performed during install or they won’t honor the warranty, and with installers making mistakes and burning up transmissions, I can see why this is their policy.

 

As long as the pump gear/rotor and converter hub aren't broken and chewed up I will warranty it.

I attended a two day transmission seminar in Mobile back in the early 90s. Gil Younger's bother was a speaker on the 2nd day. One of the things that he spoke about was how much to charge for your work. He said that you need to charge enough to be able to warranty your build twice without coming out of your pocket. You may not make any money but at least you didn't come out of your pocket. I feel that is a little harder to do these days with parts being so expensive. Back in the early 90s you could build a 3 speed unit for under $150, including the converter.

 

Damn Customers never follow your installation instructions and destroy all the time and great work that you put into these Transmissions.


"What do you mean I was supposed to put ATF in the Torque-Converter?"
"What do you mean measure and space the Torque-Converter to the Flex-Plate?"
"What do you mean verify the Dip-Stick Full Mark?"

I am so glad that I ONLY ever sold Transmissions (I did not do the installations) to carry out for some select Friends.
If I offered carry out Transmissions to Customers...
I am afraid to think of all the ruined Transmissions!

 

Yeah, more times than not I would find myself under the vehicle of a carry out build, trying to figure out what they broke. Or the vehicle is such a POS that I would have to do extra work not related to the trans install to get the trans to work. I had a guy bring me a powerglide a few months ago with the lower bolt and alinement dowel hole missing from the bell housing. He wanted me to build a unit to withstand 700 hp. I told him no way. He said that he had the missing bell housing piece that he bolts to the block, it will be okay. As soon as it breaks who's the bad guy?

 

I would say 96% success rate is phenomenal. Especially if it wasn't builder error. You can finger-inspect a planetary assembly all day and have it seem perfect to the touch and it's hiding a smoked needle bearing. Are you gonna rebuild every planetary that comes though the shop? No, of course not. No one would be able to afford a transmission if you did that (And I rebuild a LOT of planets)

I handle other people's bad installs same as I would handle my own bad install. That poop sandwich is the same amount of bites whether you're smiling or crying so why bother throwing a fit. I'm the one that can fix it, so I just do that.

People screw up. Just recently a guy bought a 750hp capable unit for his lowered, turbo'd 2005 RCSB that he had just purchased. The previous owner didnt get the spring perches welded on quite right, so the axle rolled and broke a bunch of stuff including his new transmission. I fixed it in a week, he paid for parts and I covered labor. Now anytime someone asks him about that costly incident he will not speak about how lame the whole thing was, but of how I had his back.

Now you can't satisfy everyone and being able to spot those individuals beforehand, when you're pricing them out a unit is essential. Just the other day I had some individual wheedling me for a deal. Brother, we are standing IN MY (small) SHOP next to MY (not extravagant) HOUSE. You think my overhead can get lower? what to you want me to work in the dark? get the hork outta here!

and thats my .03 cents (inflation surcharge)

 

Your the bad guy either way, If you build it and it breaks you don't know anything and can't build crap. If you don't build it you're an *** for not doing it...

 

hey sorry about my language guys, working at the shipyard gave me a big ol potty mouth

 

From what I see, thats not an issue

 

Since when does a Sailor no talk like a Sailor.

 

Guy says he has a "potty mouth," and he hasn't even said "****-****" once...

 

Personally, I’d consider that a 2% CB rate. Two people that couldn’t follow directions/didn’t ensure that the converter was fully seated in the pump, prior to install is their/an installers mistake. It’s another reason why many shops refuse to do carry outs/bench jobs for DIY folks. I’d charge for whatever parts that they broke, along with my time. I’m retired, but still don’t work for free.

 

Yeah, a 4% comeback ratio seems PHENOMINAL to me, especially when you include customer install errors.
To paraphrase Mr Bond in post #5, you might want to explicitly state in a warranty statement that "If the pump gear/rotor are damaged, the warranty is void".
I and others here have posted detailed instructions here (in old old posts) of how to install the converter and make measurements to prevent pump rotor damage. In short:
1. Make sure the converter mounting pads have a 1"+ gap to the plane of the bell housing.
2. Only tighten the trans bolts finger tight before making another measurement to ensure a gap, ideally around 1/8", between the flexplate and converter pads. A 1/8" drill bit is a good measuring tool for this.

 

Well said. If I was going to warranty a new 4L80E build, I'd provide the buyer with the following document that I wrote up which would need to be adhered to in order to not void the warranty:

https://drive.google.com/file/d/10aEcEnCt9-iRSCrXbNTG3VlOjRXtFMMZ/view

Added by mrvedit: Since I know that these online documents often disappear years later, here are the excellent instructions on installing the converter. (His document has much more install info including pictures.)

Proper Converter Installation
1. Fill the converter with a quart of trans fluid prior to install.
2. Push the converter into the transmission. Put a calibrated straight edge (something like an iGaging 12"
Hardened Steel) across the bellhousing and measure from it to the face on one of the converter pads using a
caliper or depth gage. You want this measurement to be 1.00” in – 1.200” in. If it is less, the converter is not
installed all the way and will damage the pump. Ensure that the distance from the top of the converter
mounting pads (where it mounts to the flex plate) is 1 - 1.20 inches from the face of the bellhousing.
3. Bolt the flexplate to the engine.
4. Measure from the flexplate bolt hole mounting surface to the face of the block by sticking a caliper through the
bolt hole. Ideally this measurement will be 0.875”
5. Bolt the transmission with the converter fully seated into the block
6. Without putting any bolts in the flex plate to mount it to the converter, ensure that there is a minimum gap of
1/8, and no more than 3/16 of a gap between the converter bolt mounting holes and the face of the converter
pads. Use drill bits to check. If that measurement clearance is good, you can then pull the converter to the
flexplate and bolt it up. If that clearance is not 1/8 - 3/16 and more than 3/16, then you need to add spacers
around the bolts until you get that clearance, and then pull the flexplate to the converter and bolt it up. If the
clearance prior to bolting it up is less than 1/8, then the converter wasn't made to the correct specification and
you need to contact the manufacturer.
7. Make sure that the pilot on the converter or the pilot extension on the converter is at least 0.125" in the
engine. The depth of that hole is roughly 0.300", so just make sure it doesn't bottom out in the engine and that
it has at least that 0.125 engagement. To get an initial idea, you can install the flywheel on the converter on the
bench, and measure from the top of the pilot extension / pilot to the face of the flex plate using a depth gauge.
Then subtract that measurement from the thickness of spacers that you use (assuming gap was greater than
3/16” above) and that is how much pilot engagement there will be.
8. Lastly just make sure the bolts that mount the converter to the flexplate aren't so long that they make contact
with the face of the block.

 

Yep I have that covered

 

Those are some great detailed instructions. Perhaps you guys might consider adding this to your warranty instructions: the customer must return to your shop within a specified time, so you can check fluid levels, perform a road test & get it onto the lift to inspect for leaks? We usually had road test & inspections of our rebuilds scheduled for Saturday morning.

 

That's how we did it at the shops I worked for too.
I retired from the trade in 2007 after 35 years in the trenches. I found different work but that didn't last long. In 2011 I started my own bench building service. Now at 66 I am fully retired and people still call and want work done. It's hard to turn down cash for 8-10 hours of work.

 

Both 5.7Stroker and Tranzman have posted excellent converter installation instructions. They are very similar of course.
5.7Stroker included more details specific to 4L80E installations with very nice pictures. I would suggest making it clear NOT to tighten the Bell-housing-to-Block bolts until the TC gap is measured and/or making sure the TC spins freely while tightening those bolts.
Perhaps the two of you with my help could work on a "How to install a converter" thread which would become a sticky. Each of you can make posts and I will edit them into one mutually agreeable instruction list.