Rebuild 915 tranny or buy a rebuilt one for $1,499?

[Jim Mallory]

Trying to decide which alternative is the better way to go.

Anyone have any experience buying a rebuilt 915 from Vertex?

Their price of $1,499 seems attractive. I've received pricing of approx. $2,000 for a rebuild from an indie in Atlanta.

Any advice would be appreciated.

regards,
Jim

[Jim Mallory]

FYI, my car is an 83 SC.

[tab tanner]

Whats the problem with yours? P.M. me I can help you out

[Grady Clay]

I agree, what are the issues with yours? What symptoms? What diagnostics have you done? The simplest is to document the operation – proper and other. Next would be to drain the oil and inspect the drain plug magnet. Additionally is to drop the shift pivot plate and visually inspect the gears, etc. There you should look for errant parts.

When considering a “rebuilt” transmission, demand all the details of the rebuild. Any professional will provide excruciating detail. Others … well.

Best,
Grady

[RickM]

When I had my 915 redone I used an independent who specialized in Porsche cars. He disassembled the box and asked me to come over to show me exactly what was wrong and what he'd do to remedy. He also explained what other refresh he'd perform. If possible get someone who'll do the same.

[yelcab1]

I have had the 915 rebuilt by a trust worthy mechanic, he ended up doing 3 times and not get it right. He did stand behind his work but three times was more than I can take. So, finally, I bought a rebuilt one from Vertex, changed it myself, and the problem never resurfaced again.

A Vertex tranny is not really a rebuilt one, it is really a refreshed one. They only changed the synchros, and make sure the gears are in decent shape.

So, if I were to do it again, I would just rebuild it myself, and changed everything that needs to be changed and not just the synchros.

[83SC in PA]

Originally posted by Jim Mallory

Anyone have any experience buying a rebuilt 915 from Vertex?

Their price of $1,499 seems attractive.

I know of someone who bought a 915 from Vertex with a 7:31 upgrade. The case was cracked on arrival at the installation shop and it turned out not to be rebuilt, just cleaned up externally. It needed to be rebuilt and the case needed to be welded. Vertex would not own up to any of it and this customer eventually had to pay add'l $$$ out of pocket to have it made right. You may get lucky and get a good deal from them but I felt I had to share this customer's experience.

[RarlyL8]

Vertex has a bad reputation with their "rebuilt" parts. Ask any P-mechanic who has done business with them.

The Atlanta area has to have a few good P-mechanics. Get some references here on the board and have someone local do the work for you.

[Sonic dB]

.

[Jim Mallory]

Thanks for all the replies - this is such an awesome board.

The issues are:

1. Can't shift into first until almost stopped. It does get better as the tranny warms up.

2. Shifting into second is "stiff", but no grinding (I don't speed-shift).

3. Third gear - well, now that's a mystery. 98% of the time, it is perfect. Then once in a while, out of the blue, it kicks back violently - when you least expect it. I think what's happening is that I think I'm shifting into 3rd, but I'm actually inadvertently trying to shift into first. Although the lever is in the 3-4 plane, somehow it wants to go into first! Ugh. I know ya'll are thinking it's user error. I don't think it is...but who knows.

4. Fourth is perfect.

5. Fifth is mostly perfect - sometimes it takes a little extra oomph to get it over into the 5th plane.

I got a gallon of Swepco 201, but can't get the damn fill or drain plugs to break loose. I tried using a 1/2" stubby 17 mm hex male socket along with an 18" breaker bar, but no go due to the linkage mechanism. My 17 mm allen short side is too long to properly fit - I might have to figure out a way to shorten it. Actually, with a bit of maneuvering, I can get it in, but two issues: 1. can't get any leverage, as the long side is only about 7" long, and 2. even though it's a 17mm and the plug is a 17 mm, there is a slight bit of play. Frustrating.

I would just take it in, but a local guy here wants 1 hour labor ($89) to drain/refill...and I would like to try a bit harder before I give up the money. I might just take it in a week or so, let them do it, and have them put in male plugs so it'll be a lot easier for me to do it next time.

Thanks for listening! ;-)

regards,
Jim

[coloradoporsche]

I'm in the middle of this project now:
915 rebuild...here goes nuthin!

...and what I can say is this: If you decide to rebuild a 915 yourself and replace "whatever needs replacing" you can easily spend $2000 on parts. Easily.

Follow Grady's advice and diagnose the symptoms thoroughly. If a rebuild is necessary consider doing it yourself (lots of help on this forum) or buying a rebuild from someone you trust.

I have found that Stan from Powerhaus II in Boulder CO is a reliable source of information. He claims to have rebuilt over a thousand 915s, and I believe him.

Transmission rebuilders can buy cores (lots of them) for prices in the sub-$1K range. They usually have a flat fee for an exchange, so when they get one with only a few worn parts, they ”come out ahead”. They can also buy replacement parts in volume. So the professionals’ costs to rebuild are lower than yours or mine. The question is, are thier costs low enough to buy all the necceasry parts, and do a good job for that price?

$1500 sounds like a very low price based on my research. Low is good, of course But if a rebuild is necessary, I’d shop around, talk to the rebuilders, and buy one that you feel really good about rather than going for the lowest bidder.

Regards,
Martin

[Grady Clay]

Gee, after all that hype they don’t replace the bearings and set the R&P? Sure looks like all they replace are the syncros.

It's like rebuilding an engine [transmission] without replacing the bearings!

To be fair, you can’t do everything for $1499 exchange, hehe. That is probably about right for all the shifting parts. I’ll speculate a proper 915 rebuild is $5K or more depending on parts. It is easy to see why a like new specialized transmission (oil pump, LSD, special gears, and more) can easily exceed $10K.

What would a normal rebuild include?
Eight main bearings.
The aforementioned shifting parts.
Setting the differential pre-load, pinion position and backlash.
Careful inspection of the gears, input shaft, differential, case, bearings and all the other “little insignificant issues” until one has a problem and everything has to be done over again with more new parts.

Doing these “on the cheep” is a major disservice to the cars we love and is counterproductive to their functioning and value.

Best,
Grady

[Elombard]

Whoa

I dont think you need a rebuild. I think you need to replace some bushings and reset the linkage adjustment. If it aint grinding its probably not needing a rebuild. I would buy a differnt tool to get that drain plug off...what ever it takes. Still the oil is not your problem, have you removed your shifter and looked at the ball cup bushings and the bushings in the linkage at the back (between the seats...I cant think of the name of it)????

[BGCarrera32]

The inconsistent shifting could be a misadjusted linkage and/or worn shift bushings/coupler....now having said that:

1st and 2nd gear have messed up synchro rings, 1st gear dog teeth are toast, you're also probably missing one in 3rd which you hit occasionaly causing the violent kickback...

If you have good mechanical skills/aptitude...do what RickM suggests. I did the same; I took mine apart and took the gear stacks in to a local 911 mechanic and he pointed out what needed to be replaced. I ordered the parts through him, he replaced the pieces on the gear stacks, pressed on and off bushings, etc. and I reassembled and resealed the case from there. Ran about $900 for all new synchros, seals, 1st and 2nd dog teeth, brake bands, etc. I would not personally buy a Vertex box for the reasons stated above.

I also had a totally stuck fill plug that required drastic means to remove. Take it to the local wrench (well worth the shop rate) and he'll put the necessary force on it to get it free.

Edit: and before you do anything I strongly suggest having a real 911 mechanic take it for a drive.

[Kevin Stewart]

I think i would check the coupler to see if its loose by the back seat, most of our cars cant shift into first gear until almost stopped, Kevin

[anthony]

I would check linkage and bushings as suggested.

When going for first while moving, try blipping the throttle. Also, don't jam it in first. Push it towards first with gentle pressure and hold it there. It should drop in gear.

[Wayne 962]

Transmission parts for these units have gotten *very* expensive very recently. You cannot perform an adequate transmission rebuild without replacing worn parts that are big bucks these days. The bearings are very, very expensive, and they do wear out. I would send your transmission to Jerry Woods and let him rebuild it. Guaranteed, it will come out right...

-Wayne

[rnln]

Jim Mallory,

hehe I know my tranny well by now, after a month driving it. I can't shift into 1st without an exteme force either, unless I am almost stop.
Well, sometimes I think it's good to save my tranny from my bad habbit of too gressive downshift. On my other car, I used to downshift from any gear to first to skit the rear wheels and stop :lol: well, used tranny and related parts from that car are easier to find and cheaper. Now with my 911, and with the age I am now, I would want to agressive downshift.

[JBO]

Jim - The Swepco will make little difference. I'm in Atl. and went through this decision last year. I ended up having mine rebuilt by Peter Wendt at Performance Imports, and the cost was about $1,900. Seems fine, though it still doesn't shift like a modern car, and the 915 never will. I decided on a local rebuild so if there were any problems they could be more easily dealt with. As Wayne says I have heard Jerry Woods is good, but even the good ones make mistakes, and I didn't want to possibly deal with having to pull it and ship it back. You can also drive it to a local shop and they can drive it and more easily diagnose any problems.

[fly944]

Cant you get a rebuilt 915 from Roy @ MM for like $150.00 ?