what am I looking at 915 1st & 2nd gear

[junkman300SD]

1st gear syncros are out on my 86 and it requires a complete stop. 2nd is very notch and usually requires significant effort unless speed matches perfectly.

3rd through 5th are fine. Sometimes reverse requires letting off the clutch and trying again before it goes into gear.

I don't have any history and haven't done any adjustments or changed fluid.

The local trans guy that has a rep for being competent is booked for months and known for being slow.

What am I looking at in parts and special tools? I'm thinking of learning to do my own.

[Matt Monson]

Start here:

How-To: Porsche 915 Transmission Repair Tutorial Part 1 - Porsche Wiki

[AlistairWallace]

Step 1, drain it and put in Swepco, I have tried about a dozen different fluids and that thing is like magic to that box.

Step 2, check the linkages. Even the coming to a stop problem with 1st could be caused by the linkage. If it's out or worn badly it's miserable to drive with.

Even if you decide to rebuild, the poor linkages will still make it feel like crap, so might as well you do it anyway..

[Bill Douglas]

Originally Posted by junkman300SD

Sometimes reverse requires letting off the clutch and trying again before it goes into gear.

Before you start tearing into the gearbox and spending money, I'd have a look at the clutch. It could be dragging, causing the problems.

[yelcab1]

You can change fluid and adjust the clutch and all that but ... your basket of problems means a rebuild of 1, 2 gears at least.

Syncro tools
Alignment tools
Large sockets for the gear stack
1st gear set, 2nd gear set
Syncro hubs
Syncros
Sliders

and about a month.

[junkman300SD]

I never go in and don't fix everything so expect it will be more than 1 & 2 but will try the easy things & try to get through summer.

[cabmandone]

About a grand in parts and two days work. As Matt mentioned, download Mr Z's wiki. Great resource.

A couple threads by my brother that mentions tools
Porsche 915 Rebuild - One Piece Bearing Retainer Plate
Gordo's 915 Transmission Rebuild

Originally Posted by junkman300SD

I never go in and don't fix everything so expect it will be more than 1 & 2 but will try the easy things & try to get through summer.

The 915 I did had well over 100K. Gear stack was in excellent shape. The difficulty in hitting R could more likely be a coupler adjustment where you're not getting past the R lockout tab. You might start with a clutch adjustment, check all bushings (tunnel, ball cup and shift coupler) make sure everything is good there and then assess the transmission. You'll probably still find 1&2 need work but at least you won't be going in totally blind.

[cabmandone]

This list is missing the needle bearings under the stack that I needed to replace. My ring and pinion shaft bearings were good. Some will recommend a one piece retainer which will increase cost in a rebuild. If the case needs work because the races are loose, naturally that ups the cost as well.

BTW, 3 year old price list from my refresh.

[NY65912]

I'll let you know. I am picking up my car today, first/second only. Everything else looked grat, 80K miles.

[Matt Monson]

Originally Posted by junkman300SD

I never go in and don't fix everything so expect it will be more than 1 & 2 but will try the easy things & try to get through summer.

You assume synchros on all the other gears. A 3-4 slider wouldn’t be a bad idea but might not be required. Hope you haven’t hammered the 5/R slider enough to replace it. That’s like a $500 part.

Bearings are frequently reusable for most of the box. I always suggest doing carrier bearings on the diff. However if you preorder everything just to be safe, it’s over $1000.

What am I getting at? Take it apart. Assess what it needs and then buy the parts. That’s how a shop does it. For the home mechanic it’s not a 1 weekend job, especially if you do get it apart and it needs case repairs.

[yelcab1]

Originally Posted by Matt Monson

... For the home mechanic it’s not a 1 weekend job, especially if you do get it apart and it needs case repairs.

Amen.
2 days? Hell no. It takes me one day to drop the engine and separate the gearbox between many beers. Another day to disassemble the transmission and clean things up. And then, assessment, order parts, wait for parts, send case out, etc. It would be 6 months under the current supply chain issues.

[cabmandone]

Originally Posted by yelcab1

Amen.
2 days? Hell no. It takes me one day to drop the engine and separate the gearbox between many beers. Another day to disassemble the transmission and clean things up. And then, assessment, order parts, wait for parts, send case out, etc. It would be 6 months under the current supply chain issues.

Buy a 2 post lift and work faster.

I'm not disagreeing with MM but as long as the main and pinion bearings are good, and the transmission goes through the other gears well, Out and in in a weekend tops.

Like I said, assess the situation. Make sure the clutch is adjusted, make sure the bushings are good, make sure the coupler is adjusted properly both rotationally and fore/aft and then see how it shifts. My bet is that 1/2 are crapped out. 3/4/5 are okay. But I don't have anywhere near the experience MM does so again, not questioning him. Just my experience on the transmissions I've worked on.

[Matt Monson]

Originally Posted by cabmando

Buy a 2 post lift and work faster.

I'm not disagreeing with MM but as long as the main and pinion bearings are good, and the transmission goes through the other gears well, Out and in in a weekend tops.

Like I said, assess the situation. Make sure the clutch is adjusted, make sure the bushings are good, make sure the coupler is adjusted properly both rotationally and fore/aft and then see how it shifts. My bet is that 1/2 are crapped out. 3/4/5 are okay. But I don't have anywhere near the experience MM does so again, not questioning him. Just my experience on the transmissions I've worked on.

15-20% of the job is removing and reinstalling. I’m not sure this project is the best excuse for buying a lift. At the shop I first worked at, the old timer could get one out on a jack faster than the young guy using the lift.

[cabmandone]

Originally Posted by Matt Monson

15-20% of the job is removing and reinstalling. I’m not sure this project is the best excuse for buying a lift. At the shop I first worked at, the old timer could get one out on a Jack faster than the young guy using the lift.

Any excuse to buy a lift is a good excuse!

Done it both ways multiple times by myself. I'd go lift all day every day and twice on Sunday. But I have a hydraulic lift table that is setup for removing my engine and transmission too so there's that.

BTW, when I say 2 days, I'm talking two very full days. Not an 8 or 10 hour day. I'm talking out in the shop at 7am. Engine out by no more than 11am. Trans removed and stripped by no more than 3pm. Clean, clean, clean... then get to the work of refreshing.

Would you agree that for the average 915, my list plus needle bearings would be a good jumping in point. I know what you're saying on the carrier bearings but those are fairly easily inspected. If parts are needed, naturally that extends the time for completion as I think I mentioned above.

[Matt Monson]

You’re taking my more than a weekend job the wrong way. I’m not talking actual hours. I’m talking about there being pauses to order the right parts and/or case work. My comments are in context of my other remarks.

[cabmandone]

^^^
I follow ya.

Like I said, not saying you were wrong either. You have WAY more experience in this than I do. It's an apples and asparagus like comparison.

[junkman300SD]

I've wanted a shop & a 911 for years and just bought the 86 and built a 30x40' shop that's got 13' walls. A 2 post big enough lift a 3/4 ton cummins truck is in the plan.

Getting anything construction related done is hard and expensive. 2" conduit is $30 to 40 for 10'. Send me a pm if you know an electrician in middle TN.

Back on topic, I'll be reading & watching vids. One big thing is a proper assessment & knowing what should be replaced and what is good for the long-term.

[cabmandone]

Originally Posted by junkman300SD

I've wanted a shop & a 911 for years and just bought the 86 and built a 30x40' shop that's got 13' walls. A 2 post big enough lift a 3/4 ton cummins truck is in the plan.

Getting anything construction related done is hard and expensive. 2" conduit is $30 to 40 for 10'. Send me a pm if you know an electrician in middle TN.

Back on topic, I'll be reading & watching vids. One big thing is a proper assessment & knowing what should be replaced and what is good for the long-term.

I'd highly recommend a Challenger CL10v2 lift when you get around to it. I lift everything from my lawnmower to my F250 on it. Check out those two threads I linked from my brother. He does a nice job breaking things down. Assessing parts is pretty much a judgement call. Naturally a professional shop would just replace everything because their name is on the job. Just take your time and everything will be fine. I admittedly had a leg up with my brother having done this and being my guide in doing mine. This site is loaded with experience. Matt is one of the better resources for information so definitely pay attention to what he says.

[yelcab1]

Originally Posted by cabmando

Buy a 2 post lift and work faster. ....

I have a lift. This is last weekend.



But an aircooled 911 engine drop-install is faster on jackstand. This is a month ago.



Rebuilding a 915 box is not done in one weekend, not by me anyway.

[alexandervdr]

I will do the same exercise on my 915. I will not start until I have ordered and received all the parts (to make sure I don't immobilise my car while waiting for parts) , basically the list as published by Cabmando in post #8 (for all gears while I am at it) in the thread plus the tools. I will set the valve gaps too while the engine is out. Being a hobby mechanic with plenty of time, I still count on a month to go through all of it. As a preparation, I have read and reread, viewed and reviewed about anything related to working on a 915.