700R4 Install - Updates

Ive had the car running, but have encountered several snags:

So, ive yanked the box back out again and i'm getting it rebuilt by Andy Frost Race Transmissions / Penn Autos Wolverhampton / ANDY FROST RED VICTOR 2 - whilst its in bits were upgrading all the bits inside it, to make it good for over 400ft/lb of torque.

Here's whats going into it:

26 element sprag

That lots plus various other bits and bobs comes in at $600 + $200 shipping - Ouch. Plus Rebuild costs, new Torque Convertor and a TransGo shift kit - Dont buy the B&M Shift kits for 700r4 they contain a couple of springs and an oil filter, they are crap.

The rebuild has cost quite a bit of cash, the parts from the states cost about £500 , + £300 for rebuild + £50 for transgo shift kit + £230 for std stall converter.

Update 15 Aug - Newly Built Gearbox Faulty

Once the rebuilt gearbox came back from Andy Frost, after fitting it (On my own as usual) it didn't work, No drive in "D" and it was making a noise when pulling away.

Spoke to Andy, said he needed the whole car back for diagnosis.So had it sent up there on lorry (cost me £110 quid - Grr) Andy pulled the box and after realising that the one-way sprag was round the wrong way, this was quickly fixed and the box re-fitted. When I arrived to collect it, He commented that the engine felt very flat and indeed when I arrived in Wolverhampton for a test drive, I agreed that it was very flat - however we disagreed on the cause.

I felt that it was changing gear too soon and not kicking down correctly, Andy suggested that it needed tuning on a dyno. It was much worse to drive than when the TH350 was in it, so I found it hard to believe that there was a problem with the engine, because nothing had changed except the gearbox. He didn't seem that interested in discussing the issue any further and I didn't want to get into a blazing row over it, so I left and drove it home.

Despite my fears the drive home was un-eventful (Its the furthest ive driven it on megasquirt, and I had only driven it 1 mile with the 4speed in it)

Looks like the props are OK too, they don't seem to vibrate anything like i experienced when i fitted it the first time.

When I got it back, I checked all the fluid levels, checked the timing and re-gapped all the plugs and cleaned the air-filter. It still felt flat, Its like driving a car thats in fourth gear when you should be in second. Flooring it from a standstill would result in a gearchange at about 2500 rpm - nowhere near where it should be.

So I ordered a B&M governor calibration kit from Jegs (Real steel no use as usual). I pulled the governor that was replaced by Andy during the rebuild and noticed that it was completely different from the one that was replaced, so as a first step I thought I would try the original governor back in it.

I Went off down the road, hay presto WOT changes are at 5500 in first three gears, I am now much happier with the box, apart from the high cost of the swap, I much prefer the four speed box - pulling away is good with the low gearing (3:1 ratio + 1.2 transfer box) and when it drops into fourth the revs drop down nicely. So much for it needing "tuning on a dyno".

Overall, the rebuild job seems good - So its fingers crossed that the box lasts and doesn't go wrong.

5 Dec 2004 - Gearbox slips in 4th

The car has gone back to Andy Frost Race Transmissions again; The box has a slight slipping in 4th gear only around 70-80 MPH 10 Jan 2005 Gave up waiting for Andy Frost

After wating over a month and numerous phone calls chasing progress (which were never returned), I collected the car from Andy Frost Race Transmissions / Penn Autos, still faulty. It still slips in 4th gear - Andy thinks the Valve body is faulty. His advise is to fit a manual valve body. I'm not happy with his level of service.

Moving forwards; One option is to fit either a .500 or .570 boost valves to increase line pressures (Although I have no idea whats currently fitted, one of the downsides of not rebuilding yourself) or to fit a TCI full reverse manual valve body. I'm going down the Manual Valve body route, basically this increases the pressures massively and allows me to hold it in any gear I desire. My only concern will be the harshness of the shifts, TCI tell me you can tone it down by reducing line pressure - We will see!

The only thing I managed to retrieve from Andy was the fitting instructions for the shift kit, An interesting point is that it states that the box must shift back down to 1st gear after a light throttle 1-2 shift - it doesn't do this. Also the pressures look a bit on the low side, according to the ATSG manual - the lack of a 2-1 downchange is why it feels flat sometimes when you 'boot' it when going slow. Ive now got the TCI manual valve body waiting to be fitted - lets hope that makes a difference. 21 Jan 2005 Fitted manual Valve body

Spent the whole day fitting the TCI Automotive full manual reverse valve body for the TH700R4.

The TCI valve body kit comes complete with a .500" TV boost valve & purple spring, A new corvette 1-2 servo piston, lockup solenoid wiring harness and has a new pressure switch fitted on the valve body. (you need to have a two wire solenoid). I chose the 376015 with engine braking. It cost me around £340 shipped & duty to the UK. ($170 shipping - rip off!). I also ordered the 893000 ATSG technical manual also. TCI fitting instructions for the valve body can be found here

These two photo's are for my reference showing where the check balls (ball bearings) are located on the upper separator plate:

The new valve body itself has practically nothing inside it, no valves, no springs, no TV cable, no accumulators.

Here's a photo underneath the car with the valve body removed, working upside down in a single garage on a cold day, getting soaked in ATF isn't fun.

Fitting the boost valve back into the housing is a complete nightmare. I had to grind a slight chamfer onto the middle valve to ease it in and I also modified my circlip pliers to make picking the circlip up whilst holding the valve in at the same time easier. One thing I found, was that the circlip supplied in the kit was smaller than the hole in the body - so check yours before you spend ages refitting it.

After all that time and money, sadly it didn't solve the slipping in 4th gear. Spoke to Andy Frost, in his own words "I have no idea what's wrong with it". I'm happy with the manual valve body, shifts are VERY firm but not clashy - they are like wide open firm shifts - but at any speed. It changes up and down in a split second with no delay - really nice.

You have to careful with it though, because it will do anything you want - including putting it into 1st at 50 or 100 MPH! - The B&M ratchet shifter works well with it though.

25/1/05 Solved problem myself

Finally solved the slipping fourth gear problem myself, after pouring over the ATSG service manual and chatting with people on the hotrodders forum, the next thing to look at before a complete tear down was the servo.

On a 700r4 (or 4l60), 2nd and 4th gear use a band which is actuated by the servo you see sticking out the side of the case. 3rd uses the 3-4 clutch pack and fourth applies the 2-4 band to the allready applied 3-4 servo (hence its name) So the theory goes, if the band is slipping it would slip in 2nd and 4th and if the 3-4 clutch pack was slipping - it would slip in 3rd and 4th - however I learnt that there is two circuits and pistons for the band, A large 2nd apply piston and a smaller 4th apply piston and they both apply pressure to different parts of the pin that applies the band.

Also the shift into 4th was still vague and slow, even with 250+ PSI line pressure against it. I pressure checked the 4th Oil test port and it was seeing 250+ psi also

Recall that I fitted billet super servos, the 2nd piston is "Superior" brand and the 4th is a "Sonax" part, after pulling the servo assembly out, a big washer immediately caught my attention - this was preventing the 4th piston fully pressing on the pin.

(Put your mouse over each photo)

I wrote a letter to Andy Frost detailing how I repaired the box myself asking for a little compensation for the money and time I spent repairing his workmanship - He never replied.

So he may have the Worlds Fastest and quickest Vauxhall pump gas car, but his customer service - at least in my case was very poor.

24/2/08 Postscript

Andy frost finally said sorry, Admited he got a few things wrong with my box. Fair enough, move on.

7/5/05 Gearbox Failed

Car on the road after twin turbo's fitted, gearbox lasted about 50 miles. Stripped the box down, turns out that both the snap ring grooves on the input drum have been completely smashed out. General consensus is that its caused constant high line pressure that's a feature of the Manual valve body (it doesn't have a TV valve or cable)

Obtained a post 87 gearbox for rebuild, going to try putting the later drum in my early box. Shed is looking like a 700r4 graveyard now...

16/5/03 Repaired Gearbox

I have Successfully rebuilt the box using a post 87 drum in a pre 87 box. I now intend to do a full 600bhp rebuild using the torque drive drum on the spare 700r4, so I will have a spare gearbox for future failures(!)

I swapped the purple spring that came with the TCI kit with the green spring in the boost valve, retaining the .500 valve - still seeing 250 psi, so need to figure that one out yet.

During the rebuild, I Came up with an easy way to install the solid teflon seals on the stator shaft, just use a piece of thin mylar sheet (the stuff on the front of manuals), wrap it around the shaft and slide the seal down. You will still need to resize the seal, this is done by using a piece of tube with a 1.1" (28mm) diameter with a generous taper at one end. Gently slide the sleeve down over the seals and they will squash down to size.

I also made a DIY spring compressor, as shown:


une 2005 Removed Manual Valvebody

Gearbox Line pressures were still wildly flutuating between 230 and 250psi so I decided to refit the original auto valve body as i'm worried it will break the input drum again. Line pressures are now 90psi idle and 150psi at WOT.

14/08/05 Gearbox Fails again

Gearbox expired again. Lost 3rd gear racing with a Audi RS4. Lasted about 700 miles. Building a new box from scratch using all stage 4 parts, guess it will last about 1400 miles then!

Update: Prognosis in my view is two-fold: 9 Plate Alto clutch steels are too thin AND you need much more than 150psi clamping pressure at WOT. Dont build a box to the above spec, use the spec on the next page. And if you can, do the work yourself.